EarSonics Onyx


Catastrophic manufacturing
Pros: Powerful and rather textured bass
Fairly detailed mediums
Fairly ample scene with a nice depth
Cons: Cable worthy of a pair of intras at 10 dollars
Finishing, catastrophic!
Poor packaging and accessories not included (an oversight)
I will be brief. Because as much the sound has been analyzed fairly fairly on the previous tests, there is a point to highlight, especially on intras of this price with a small Parenthesis concerning their high ranges, Platinum Grace.
What is the point of having a good sound if the manufacturing quality does not follow! Catastrophic machining, deplorable finishes with deviations of adjustment unworthy of a pair of intras at 5 dollars. A vent has even been forgotten to be pierced! I have never seen this.Finally, accessories that were not included because it is an oversight. The photos speak for themselves! Even my Grace Platinum have platinum veneer which disintegrates after a few months. Knowing that I don't use them often! In short, it had to be mentioned all the more since, sound level, there is Alternatives. And much better manufactured. These intras were purchased with my money, and were returned for a refund.


  • 1000015626.jpg
    1.7 MB · Views: 0
  • 1000015618.jpg
    1.8 MB · Views: 0
  • 1000015628.jpg
    1.8 MB · Views: 0
  • 1000015620.jpg
    2 MB · Views: 0


1000+ Head-Fier
Awesome Price for this IEM
Pros: Insane Build Quality
Surprising Sound Quality
Good Mids
Good Highs
Decent Packaging/Accessories
Cons: Meh Lows
A little heavy
Just OK cable
Meh Soundstage/Separation/Imaging
Onyx Front.jpg

Original Logo Small.png


Up for review today is the Earsonics Onyx – a relatively unknown IEM from a relatively unknown brand. The Onyx has 4 drivers with a mix of DD and BA – I’m not sure how those are spread out since their own website doesn’t really tell you, but I’d have to guess DD for bass and Bas for the rest. I received these from a fellow Head-Fier to test out since he lists them as his best under $1k – an award I give to the FiR VxV or CA Andromeda, but damn if I’m not tempted to recommend these instead for very different reasons. You can buy these from Audio46 for $639 retail if you want a pair. Yes, I forgot to photograph these, so you get stock images, my bad. On with the review!

Onyx Cable.jpg

Accessories/Earpads/Eartips (8/10):

Not bad Nick, not bad (if you get that movie reference, you’re cool). A decently nice black box (duh), a decent, if not amazing cable, a cleaning tool, 6 sets of ear tips of various types (sweet), and a perfectly serviceable black carrying case. Yeah, this is about what I expect at this price level – it’s a better package than far too many kilobuck IEMS. Still, it’s nothing mindblowing, and it’s still not quite as nice as what TRUTHEAR offers in their $80 HEXA packaging (still a gold standard), so overall it earns a solid 8/10 points. The Spinfit W1s are too big for the nozzles on these – the Final E type fits better.

Onyx Connector.jpg

Cable (6/10):

Yeah, it’s OK. It’s 3.5mm, which isn’t ideal at this price range – most people paying this much for an IEM likely have a balanced connection of their DAP, even if it’s only the Shanling M3U, etc. Heck, the TRUTHEAR SHIO has a 4.4mm, so it’s not the best, but it functions perfectly fine. It appears to be a silver-plated copper cable, and it feels a bit cheap, and very thin overall, but again, this is not a kilobuck IEM. The Aroma Thunder comes with a worse cable at 3-4 times the price. So yeah, it’s not great, but not bad either – 6/10 points.

Onyx Side 2.jpg

Build Quality/Comfort (9/10):

Holy crap, they built these like a friggin’ tank. This is an all-metal IEM and makes stuff like the $5k Jewel or the $6.6k Traillii look like a cheap toy. So yes, the build quality is great. The design looks really great here as well – someone went to design school. The black Anno on these feels durable and my used copy came with no scratches or blemishes, which is how IEMs should look, but my Mentor somehow managed to pick up a scratch on the “gold” trim despite how careful I was with them, so this is really nice to see.

The comfort is good, and these are designed really well, but they’re not the smallest or lightest IEMs ever. The all-metal design makes them pretty heavy and they are pretty thick and somewhat large – not Ronin large, but still bigger than almost anything from Campfire Audio for example. The weight can get uncomfortable after long listening sessions, so it’s something to consider. 9/10 points here.


Check out the wolfhawk.squig.link below to see how these compare to…well…nothing really. I don’t much that is in the $6-700 range. The closest thing I have is the Kiwi Ears Orchestra Lite and while it’s not too far off, it’s still pretty different – not to mention the price difference. So, the Onyx has some solid bass and sub-bass, but not mind-blowing, and somewhat recessed mids according to the FRG. The highs are nice and tapered off, which might help or hinder the Onyx on the songs below. I included the Andromeda 2019 I just got as well since it's probably the close I have here price-wise, though they graph like polar opposites.

Onyx OL Andromeda.png

I’m driving these off of my new Cayin N8ii DAP on solid-state with medium gain at around ~35/100 volume. That’s really good for a 3.5mm unbalanced connection – bravo Earsonics. I’m using Tidal Hi-Fi Plus to power it with MQA on.

Lows (14/20):

I’m starting off with the Mid-bass/Sub-bass test I’m using David Guetta’s “I’m Good (Blue).” There’s some really ghood impact here, but it does feel pretty thin compared to some, admittedly, much more expensive IEMs. The sub-bass has some really good body to it, though it’s pretty fuzzy. These have some really solid bass for the price, but it’s not at the quality level I expect from a more expensive IEM. It’s slightly above average, so it earns a 6/10 here – great quantity, ok quality.

Up next is Demon Hunter’s “I Am A Stone,” which I use to test whether the bass is too strong and overwhelms the mids as that is just as important as how strong/good the bass is. You really need to crank the volume here to hear the mids well – that’s thanks to the massive mids dip on the tuning. Still, the bass doesn’t really overwhelm the mids here and it’s a good overall presentation – again, for the price. It’s a really nice and full-bodied presentation here, though the recessed mids are not to my preference. 8/10 points here.

Mids (16/20):

Weaving The Fate’s “The Fall” is my test song for clean/dirty guitars and vocals with background instruments to see how clearly the vocals can be heard. The intro guitars are nice and clear with some really good dirty guitars. There’s a really warm, full-bodied presentation here. The downside again is that you have to crank the volume to really get the full presentation of the mids. That raises the volume of the lows as well and makes them a bit more present than I’d like on this song. Still, the overall is really quite good and it earns the Onyx 5/6 points here.

Staind’s “Something to Remind You” has clean electric guitars and wonderful vocals – this song tests vocal quality and background noise. The Onyx really has an amazing ability to present music in a warm and inviting manner that a lot of more expensive IEMs can’t do. This song is a great example of how that is presented. The vocals are great, the guitars are great, the soundstage feels intimate, but still large. It’s a fantastic presentation here with all of the details I look for in this song. 7/7 points awarded.

To test classical instruments in the mids, I’m using The Piano Guys' “Code Name Vivaldi.” While this song sounds quite good and has plenty of the motion ‘m looking for here with this song, the mids come in too recessed to really bring this song to life. The low-mids sound fantastic here with the bass-cello and the drums taking the front, but it leaves the piano and the mid-cello lacking without turning up the volume to uncomfortable levels. 4/7 points here.

Highs (15/20):

To test sibilance on headphones I use Panic! At The Disco’s “High Hopes.” Yeah, there’s some sibilance here, but it’s relatively controlled and certainly above average. 4/6 points here for decent sibilance control.

Dream Theater’s “The Alien,” is the highs test song I use to see if the cymbals/high-hats/snare drum can be clearly heard and distinguished from the rest of the music (also good for instrument separation.) There’s surprisingly good treble on the Onyx. Cymbals can be heard quite clearly against the rest of the song in the intro. Drums are also at the front of the sound presentation as well. I wasn’t expecting to be able to hear any treble based on the previous songs, so this is a welcome discovery. 6/7 points here – it’s surprisingly good, though it’s important to note that the mids do feel very recessed here.

Michelle McLaughlin’s “Across The Burren” is another of my favorite highs/sharpness test songs as it can easily sound painful on some headphones. Oof, there it is. I was really wondering where the weakness was going to be in the highs here since there’s almost always a weakness. It’s here with the sharpness – pretty painful. I was able to get through the whole song but it was definitely rough in some spots.

Soundstage/Instrument Separation/Imaging (6/10):

I use MGMT’s “Time to Pretend” to test soundstage, instrument separation, and imaging. Wow, not bad at all – these are how much again? There’s a very large soundstage, even if it’s pretty forward-leaning like most cheaper IEMs (2/3). It’s not anywhere near TOTL levels, but it is surprisingly good. The instrument separation is good, but not amazing (2/3) points and the imaging is again, good, but not TOTL (2/3). That’s still a really impressive score for this price range. 6/10 points awarded.


I just got a 2019 CA Andromeda in and despite their MSRP differences, these two both sell for around the same price on the used market (maybe a little less for the Onyx, they’re so rare it’s hard to tell). They actually feel like very similar IEMs though the Onyx has a bassier presentation and an excellent soundstage and an all-metal construction. The Andro has more forward mids though and it’s my overall preference, but I also really like Campfire’s house sound as well. The Andro is also lighter and smaller, thus more comfortable. Both come with equally crappy cables, though I’d put the Onyx’s cable as the better of the two since it tangles less. Still, if you can get the Onyx for around $400, it’s a steal since an Andro will still run you $500+ in good condition – assuming you can find one. The Onyx has highs that are pretty close to the VxV for quite a bit less. It also has more bass, the recessed mids are the place where the Onyx easily loses out to the VxV – they’re really good mids, but they’re too quiet compared to the rest of the soundstage – something you may be able to fix with EQ.

Onyx Side.jpg


Wow, the Onyx surprised me. For a company that I’ve never heard of before, these are really cool IEMS. If you’re looking for some good bass quality, but not too much bass quantity, some high-quality mids, even if they’re too recessed, and some really good highs with a bit of sharpness – all for far less than a TOTL IEM, these are a great choice. Yes, I had to play with the volume a lot to get the best sound, but these will definitely go down as one of my best IEMs under $1k – quite a bit under. If you want to give this relatively unknown IEM for a relatively unknown company a shot, don’t hesitate – grab a pair.

Headphone Scoring (v3):
Accessories / Earpads / Eartips (10 pts):
Cable (10 pts):
Build Quality/ Design / Comfort (10 pts):
Lows (20 pts):
Mids (20 pts):
Highs (20 pts):
Soundstage / Instrument Separation / Imaging (10 pts):
Last edited:


Reviewer for The Headphone List
ryanjsoo's Reviews
Earsonics ONYX Review – Expect the Unexpected
Pros: Class-leading build quality, Nicely balanced W-shaped signature, Awesome bass power and control, Very spacious stage, Very Easy to drive
Cons: Treble resolving power just average in-class

Ergonomics and build perform at the highest level and its sound is engaging yet tasteful, retaining overall balance. It is my pleasure to recommend the ONYX for those wanting an engaging midrange IEM.

Introduction –

Earsonics is a French audio brand that has achieved a solid international presence with their high-end IEMs. The company initially made waves with their all-BA reference monitors and have since tried their hand at hybrid designs that came alongside new metal shells. The ONYX is their latest project which finally sees the light after having been teased for quite some weeks. This model seeks to fill out their product lineup with a more affordable option. In fact, the company was so dedicated to value that they are only offering this IEM directly to consumers rather than by distributors to cut out middle-man costs. The result is an IEM that implements technologies and specifications seen on their pricier models at a far more accessible price point.

The ONYX just launched for 590 EUR at the time of writing. You can read more about it and treat yourself to a unit directly from Earsonics here!

Disclaimer –

I would like to thank Thibault from Earsonics very much for his quick communication and for reaching out to organise a review of the ONYX. All words are my own and there is no monetary incentive for a positive review. Despite receiving the earphones free of cost, I will attempt to be as objective as possible in my evaluation.

Specifications –
  • Driver: 1x DD, 2x BA mid, 1x BA high
  • Impedance: 16.5 ohms
  • Sensitivity: 122 dB
  • Frequency Response: 10 Hz – 20 kHz

Behind the Design –

Hybrid Drivers

Like many modern high-end IEMs, the ONYX uses a hybrid driver setup with a single DD woofer, 2x BA mids and 1x BA treble. The company is using HQ low-variance discrete components alongside proprietary, impedance-matched drivers designed to their spec. The company also reasons that this makes the earphone easy to drive from a variety of sources.

Acrylic Heart
At the core of the ONYX is the acrylic heart which is a 3D acrylic acoustic chamber. It provides support for the drivers in addition to reducing resonances. Specific positioning of each transducer to provides phase coherence alongside the company’s desired frequency response via a 3-way passive crossover.

The output nozzle of the earphone implements a specifically designed bell and tuning resonator that corrects the frequency response following the acrylic heart chamber. It serves to further optimise phase coherence and reduce resonances that may harm high-frequency extension.

Unboxing –


The earphones come in a handsome black box with a soft-touch finish and “ONYX” branding in gloss film. Opening the magnetic latch reveals the IEMs within protective foam inlets with a standard zipper carrying case below. To the side is a separate compartment containing the accessories. Out of the box, Earsonics provides 2 pairs of silicone ear tips, 2 pairs of Comply foam ear tips and 2 pairs of dual-flange tips. In addition, the ONYX comes with a cleaning tool and paperwork for authenticity.

Design –

Earsonics’ recent shell designs have been a beautiful display of metalwork and the ONYX is no different. These earphones employ shapely all-metal 2 piece shells with an almost Daft Punk-esque aesthetic. The texture tells me these are injection moulded rather than CNC shells giving them an awesome satin finish. Despite this, the tolerances are excellent with nigh-perfect faceplate matching and smooth, well-finished edges all around. The ONYX is an earphone to be enjoyed both in and out of the ear with craftsmanship that is best appreciated close-up.


Above, users will find the widely adopted 0.78mm 2-pin removable cable interface. The stock cable offers sound quality, a 4-core unit with a braided design and soft, transparent insulation. It sports 4C-HR silver conductors. It is rather thin and a little rubbery, but still offers sound ergonomics and minimal microphonic noise transmission. The metal connectors provide contrast to the dark housings and the pre-moulded ear guides offer a comfortable and stable fit for my ears. Earsonics also offer an upgrade cable at an additional cost of 199 EUR.

Fit & Isolation –

From visual inspection, I wasn’t sure what to expect from the fit as Earsonics’ IEMs are one of the more unorthodox silhouettes on the market. Colour me impressed for the ONYX provides excellent comfort and stability on behalf of their shapely and well-contoured design. I was able to wear them for hours at a time without discomfort or hotspot formation. Though the shells are slightly larger than average, those with average-sized ears should have no difficulties. Their ergonomic shaping helps to achieve excellent articular fit with the concha, aiding stability and minimising hotspot formation.


The well-angled nozzles also contribute as they position the housings flusher with the outer ear contributing to an impressively low-profile fit despite the width of the shells. The well-angled and slimmer nozzles produce a slightly shallower than average fit depth. In addition to their vented design, wearing pressure is kept to a minimum. In addition, isolation is above average and easily suitable for daily commute whilst permitting some spatial awareness. It should be noted that some driver flex is apparent despite their vented design, however, I did not find this to affect reliable function or performance during my testing. Those wanting the best isolation for especially noisy environments may still want to investigate a fully-sealed option that said.

Sound –


Testing Methodology: Measured using Arta via IEC 711 coupler to Startech external sound card. 7-9KHz peaks may be artefacts/emphasised due to my measurement setup, less so with a deep fit. Measurements besides channel balance are volume matched at 1KHz. Fit depth normalised to my best abilities to reduce coupler resonance. Still, due to these factors, my measurements may not accurately reflect the earphone or measurements taken by others. I gave the ONYX 100hrs burn-in to ensure maximum performance prior to subjective breakdown.

Tonality –

The ONYX has an intriguing sound tuning that is quite different in measurement to many competitors but provides a perfectly natural voicing during listening all the same. In direct comparison to something more linear in its tuning, the ONYX has an intriguing W-shaped character with exaggerated separation between each frequency band. This character begins with a modest bass emphasis equally focused around the sub and mid-bass regions instigating a bold, meaty low-end with an abundance of power and drive. A sizable upper-bass/lower-mid dip aids a well-separated midrange and prevents spill. The midrange employs dual 1.5kHz and 4kHz humps meaning both male and female vocals are brought forward with instruments sitting behind. They occupy an intimate position in-line with the bass. Finally, a 6kHz peak provides a crisp, energetic top-end that serves as a foil to the thick bass and big midrange. Altogether, a unique and well-executed earphone that upholds respectable balance whilst oozing loads of personality.

Bass –

As the mids and treble have been brought up to a similar degree, Earsonics was able to achieve a powerful voicing without bass dominance. To my ears, they have a slight sub-bass bias though mid-bass does sit roughly on par so as to avoid upsetting balance and timbre. This provides enlarged bass notes with a thick, weighted character. The dynamic driver also extends terrifically, it has a good amount of pressure and a visceral rumble. As the mid-bass has also been elevated, the low-end sounds consistent between tracks with no shortage of punch and impact on albums mastered with less sub-bass. The earphones also have a much narrower bass shelf than many bass-boosted IEMs, with a steep drop above the mid-bass through to the lower midrange.


Accordingly, they aren’t especially warm nor are they bloated or tubby. The ONYX delivers a focus on excellent dynamics, slam and power. The note presentation plays into this as well as Earsonic’s dynamic driver provides a keen, tight attack and well-controlled decay. The ONYX has a very well-defined bass, especially when taking its level of emphasis and style of tuning into consideration. Sub-bass slam is tight, well-paced and satisfying. Notes decay slightly quicker than neutral, redeeming separation. Though the thick note structure means this isn’t a defining feature of the ONYX’s low-end, it also never presents as muddy or smeared on complex tracks. This is a responsive, technically impressive bass response with a well-executed fun and engaging character.

Mids –

It’s impressive that despite the robust, powerful bass, the midrange manages to draw equal focus and it does represent ingenious colouration on Earsonic’s behalf. Those wanting utmost linearity and balance may find the vocal/instrument balance leaves them wanting. However, for sheer musical enjoyment, the ONYX is an appealing package that genuinely surprised me. For instance, the earlier 1.5kHz rise brings male vocals forward and the smaller 4kHz lift equally services female vocals. This is a refreshing change from many IEMs that have more of an upper-mid bias so, if you like male vocals, the ONYX presents them with awesome clarity, size and definition. The 4kHz bump combined with reduced note body from the lower-mid dip means the ONYX has a more revealing character within the midrange itself though never in an intense manner.

Hints of warmth seep in from the bass preventing the monitor from presenting as sterile, metallic or cool. I also find the earlier 1.5kHz emphasis gives vocals a bit more size and gusto than your usual 2-3kHz emphasis. The result is large, intimate vocals that aren’t perfectly natural coming from more linear reference monitors, but impressively close despite the colouration. The ONYX is quite an articulate monitor on top which helps to bring small details to the fore. Since treble emphasis is on equal footing with the ONYX’s forward vocal range, it also isn’t head-voice dominant or sharp. Altogether, the ONYX doesn’t sound explicitly linear, but it does have a lack of unnatural qualities. Moreover, it does so with awesome vocal definition and separation from the bass and excellent clarity without intensity or rasp.

Highs –

We tend to innately focus on the top-end performance when first evaluating a high-end IEM as treble extension and sparkle have since become unanimous with these designs. However, in actuality, this does not necessarily have to be the case. The ONYX proves this as its standout features are surely its bass and midrange. Treble, meanwhile, performs at a good level but doesn’t strike as being so outstanding. It has a moderate 5.5-6kHz peak that instigates a slightly more energetic foreground treble presentation. It doesn’t quite have the precision and fine resolving power here of class leaders, but an average amount augmented by a crisp and engaging tuning. I find the leading edge isn’t over-sharpened despite the tuning and the ONYX has a surprising amount of body and texture if here at the expense of raw note definition. It still separates well and provides a mostly natural timbre that is easy to enjoy.


Above, the tuning quickly falls off, providing a clean, black background. This gives the earphone a hyper-contrasted foreground/background that contributes towards an enjoyable layering experience. While background and micro detail in the highest registers won’t win any awards, there is enough information here to provide a well-defined background to enable a good sense of distance projection. I do believe the treble will be one of the more polarising aspects of this earphone as it doesn’t present as especially well-extended or open. Perhaps, more overt brightness and sparkle here would have made the overall presentation more fatiguing given the already engaging bass and midrange tuning. To my ears, this has always been a defining characteristic of Earsonic’s designs and it does make sense when taken as an overall package.

Soundstage –

Despite the darker treble tuning, I found myself impressed by the soundstage performance of the ONYX. It showcases well above average dimensions with width especially stretching nicely beyond the head. Depth is no slouch either, but the stage proportions are ovoid overall. The imaging performance is also one of the best performers in class. The ONYX has a very strong centre-image and a fairly keen sense of direction too.

It doesn’t have many layers or dissect vocal harmonisations like a TOTL monitor but has a hyper-defined foreground and dark background with good contrast. Separation is also quite good, especially impressive given its thick, weighted bass. The ONYX has a well-controlled bass response with excellent separation to the midrange and treble. The upper-frequency ranges themselves lie on the revealing side with a slightly thinner note body meaning there is a sense of ether surrounding each element. This makes small details easier to perceive by the listener.

Driveability –

With a regular 16.5-Ohm impedance and a 122dB sensitivity, the ONYX is an efficient design suitable for portable sources. I found this to be the case during testing as well, hitting ear-splitting volumes from low powered dongle-style sources yet alone DAPs and desktop gear. The upside to this as well is that the ONYX sounds dynamic and well-voiced from lower power sources too making it easy to live with.

Output Impedance Sensitivity


Fortunately, the ONYX has a relatively flat impedance curve and this is something I confirmed in subjective testing as well. The rule of eighths dictates that the sound will only be as the designer intended from a 2-ohm source, however, even from a source with a 20-ohm output impedance, the sound signature remains essentially unchanged. This bodes well for performance from integrated audio solutions in laptops and phones for instance, that often sit around a few Ohms and can skew the sound of most multi-driver in-ears. The ONYX has a very consistent character between sources which widens suitable pairings.

Driving Power

Similarly, the ONYX is an efficient earphone that I didn't find to require much driving power. Switching from the Shanling M2X to my desktop stack with THX789 revealed a small jump in dynamics and sub-bass definition but a similar voicing otherwise. The Astell & Kern Dual DAC cable drove the earphones just as well as the larger DAP making this earphone a great choice for those without high-end sources. Though the sensitivity is high, they aren't overly hiss sensitive. On the M2X with the amp circuit active and volume on 0, hiss was vaguely audible but completely inaudible when music was playing.

Suggested Pair Ups

The ONYX is a very easy to drive earphone which adds to the value proposition as ideal source pairings aren't a requirement to derive an enjoyable sound. It plays well with higher output impedances and lower-powered sources but does scale nicely with regards to dynamics and soundstage size from better sources. Hiss also isn't a huge concern on this design. Given its sound signature, I found neutral-leaning sources were to my preference as their keep the low-end as clean as possible. However, it also isn't an especially warm or stuffy sound so there is leeway for warmer sources too. There is also ample body to enjoy them with bright sources but I did find the midrange was a little thin.

Comparisons –


Etymotic EVO ($499): The EVO is a far more linear earphone with a much flatter bass. Given its all-BA setup, the ONYX has a large advantage when it comes to bass power and extension. The EVO is quicker, leaner and faster while the ONYX has a much bigger bass in general with a lot more sub-bass and a fuller mid-bass. The ONYX is far more dynamic. Despite this, the ONYX has equally forward vocals to the EVO. The EVO sounds more even here and its voicing is more accurate. The ONYX has more colouration with higher clarity and intimacy alongside a bit more warmth from its bigger bass.

The EVO resolves slightly better but the ONYX is more engaging with its more articulate and clarity-enhanced nature. Up top, the EVO is once again more linear nigh slightly smooth through the lower-treble. The ONYX has more energy and crispness here but not by a large degree. The EVO sounds more precise with a more defined leading edge and greater resolving power of fine details. The ONYX has the darker background but the EVO extends slightly better with superior background detail retrieval. Despite this, the ONYX has a much larger stage. The EVO has sharper direction and better layering.

Oriveti O500 ($499): The O500 is a good comparison as it shares many similarities with the ONYX with a dark background and intimate vocal presentation. The ONYX is the bassier earphone with the O500 having less sub-bass pressure and a few dB less emphasis above. Otherwise, the tuning is similar between the both. The ONYX is noticeably more dynamic with a harder-hitting slam. I do find it more controlled and defined too. The O500 only comes out ahead if you are averse to sub-bass pressure that some find fatiguing. The O500 has a similar midrange tuning but sustains more through the 2-3kHz range. This gives it a more vocal-focused character.

The O500 is more transparent, it has slightly higher clarity and definition and a cleaner tone. The ONYX is slightly more balanced with slightly more body that makes it more forgiving but slightly less resolving. Both earphones have a small dip before a medium lower-treble peak. The ONYX does have the more defined leading edge while the O500 is smoother and more delicate. The ONYX has more body and texture while the O500 has better extension and greater air. Both are dark and clean above, the ONYX is darker while the O500 retains a bit more headroom. The ONYX has the larger stage, especially width. The O500 separates slightly better while the ONYX has sharper imaging.


Moondrop Variations ($520): The Variations is a similar kind of earphone too. It has a big sub-bass boost but, otherwise, represents and impressively linear response. Both have similar levels of bass, the ONYX has a bit more balance between sub and mid-bass while the Variations prefers a cleaner tone with more sub-bass bias. Both have awesome extension, rumble and slam. The ONYX is slightly more controlled, boasting higher note definition and responsiveness, the Variations comes across as a bit softer despite the initial attack being just as assertive. The midrange is more forward on the ONYX. The Variations has a slightly clearer, more linear expression with a more neutral tone. The ONYX has slightly more warmth to its male vocals especially and they are a touch more forward.

Both have similar clarity and upper-mid positioning, the ONYX sounding a bit more coloured but not by a large extent. The Variations has slightly higher resolving power. Up top, the Variations is slightly smoother with a more linear lower-treble. The Variations pulls ahead on fine detail retrieval and extension by a noticeable degree. Its leading edge is more defined and its timbre is more accurate. Its background detail retrieval and extension are superior. The ONYX has a bit more body and focus in the lower-treble as is a weakness of the EST system employed by the Moondrop. But technically, it does fall behind. I do, however, find the ONYX to have a larger soundstage, the Variations has slightly sharper imaging in return.

Craft Ears Craft FOUR (625 EUR): The Craft FOUR also has some degree of vocal focus and a warmer-tonality, a fun W-shaped IEM that can be had in custom for a similar price. While both have a similar amount of mid-bass, the ONYX has more sub-bass while the FOUR begins to roll off. The FOUR has very impressive extension for a BA but can’t match the dynamics and power of the ONYX. The FOUR has a quicker decay and, in turn, its mid-bass appears punchier and more defined. The ONYX isn’t too far behind whilst boasting far greater dynamics. The midrange on the FOUR appears more forward by comparison to its less present bass while the ONYX is more balanced between the 3 frequency bands.

The FOUR has a more evident warmth and a bit more body. Meanwhile, the ONYX is one step more revealing with slightly higher clarity and extension on behalf of its more present upper-midrange. The FOUR is a bit more coherent but both are naturally voiced in summary. The FOUR has a more isolated treble while the ONYX sounds more even-handed in its delivery. The FOUR is a bit crisper but also thinner. The ONYX has more body and texture alongside a slightly sharper leading edge that gives it a small advantage on fine detail retrieval. Above, the FOUR does extend a hair better and delivers greater air due to its higher treble peak. The ONYX has the larger soundstage and both have a similar level of imaging performance.

Verdict –


It has been quite a while since I’ve listened to an Earsonics monitor; as I recall not since their acrylic reference monitors of old. And colour me impressed! The ONYX is an impressive experience from start to finish. Perhaps the simple unboxing, thin cable and treble extension are telling of its true asking price. However, the metal shells and W-shaped signature with awesome bass power and extension give the impression of a far more expensive monitor. Overall, I do believe this makes the ONYX a strong value proposition when taken as an overall package, just as the company set out to achieve. Ergonomics and build quality perform at the highest level and its tuning is highly engaging yet executed with immense mastery so as not to upset overall balance. It is my pleasure to recommend the ONYX for those wanting an engaging midrange IEM.

The ONYX is available from Earsonics (International) for 590 EUR at the time of writing. I am not affiliated with Earsonics and receive no earnings from purchases made through these links.

Track List –

Billie Eilish – dont smile at me
Bob Seger – Night Moves
Courtney Barnett – Rae Street
Cream – Wheels of Fire
Dire Straits – Communique
Dirty Loops – Next To You
Eagles – Hotel California
Elton John – Honky Chateau
Fleetwood Mac – Rumours
H.E.R – I Used To Know Her
Jasen – BYE
John Mayer – Continuum
Kanye West – Ye
Missy Higgins – The Sound of White
Radiohead – OK Computer
TALA – ain’t leavin` without you
The Beatles – Abbey Road
The weeknd – After Hours
Vampire Weekend – Father of the Bride
Great review
Thanks guys!
Excellent review, Ryan! As always your pictures are of the envious variety. I want to take photos like that when I grow up. :wink:

It is also good to see we agree with much of the intricacies of the Onyx. Well done, sir!


Reviewer at hxosplus
Black Magic
Pros: + Balanced and musical tuning
+ Great bass extension with good technicalities
+ Lush mids and fatigue free treble
+ Crystal clear and resolving
+ Expanded soundstage with accurate imaging
+ Coherent timbre
+ Great looks and mostly comfortable fit
+ Excellent build quality
+ Cable of good quality
+ Handcrafted in France
Cons: - Bass can sound hollow
- Could do with greater dynamic impact
- Upper - mids emphasis
- Some issues with treble timbre
- Bulkier and heavier than the competition
- Poor accessories pack
- At this price point a modular cable should have been included
The Onyx was provided free of charge in exchange for my honest and subjective evaluation.
The selling price is €491.67 and it is exclusively available from Earsonics.

About Earsonics

Earsonics was founded in 2005 by Franck Lopez, a musician and sound engineer, who, unhappy with the quality of in-ear monitors available at the time, decided to create his own.
In 2006, he began to offer his creation for sale and enjoyed immediate success, even equipping the biggest French music tour at the time. Earsonics was born !
Franck then decided to release a mainstream model which would appeal to markets outside of France…the SM3. The resulting product reviews expanded product awareness into the Asian and North American markets, with the SM3 considered the finest earphone ever tested.
In 2012, Earsonics launched the first universal 6 driver earphone in the world, the S-EM6. Entirely made by hand, its musical qualities garner universal praise in numerous tests.
In 2016, Franck decided to create the best universal earphone in the world, using the many advances and technologies developed up to that point – the S-EM9. With nine drivers and three exit ports per side, the aim was to be able to listen to music exactly as it had been recorded.
From its very beginning, Earsonics has always been associated with professional musicians, and it is by developing products for this industry that it has been able to offer earphones of exceptional quality to the discerning public.
More information about Earsonics and their full catalogue can be found here.

The Onyx is not my first encounter with Earsonics as I have previously reviewed the Corsa.


The Onyx project

The Onyx concept was born in a confinement context.
The team of enthusiasts engineers in charge of its development wondered what could be the best earphone that would meet the current requirement of the audiophile public.
What started out as a concept turned into a real project.
The ONYX was born.
This team of passionate people, the heart of the ONYX project, designed it based on the knowledge and know-how used in the Earsonics laboratories.
After several months of work, the first plans for the ONYX were alive and with them the beginnings of an exceptional earphone.
To develop the ONYX, using the best materials was the leitmotif of the team.
When developing it, the engineering team used the best.
Thus, the ONYX is based, among other things, on the latest generation of 3D acrylic core used for the Grace Platinum, Earsonics flagship.
The specific inclination of the ONYX body and cannula is the result of many years of research guaranteeing a comfortable fit and better insulation.


Direct sales

The project goal is to offer a very high-end universal in-ear at a price never seen before.
It was therefore necessary to reduce distribution and processing costs as much as possible.
In order to achieve this, Earsonics decided to set up a direct sales website for ONYX without any intermediaries.
The ONYX is exclusively available to order on its dedicated page.

Handcrafted in France

Entirely handcrafted in France, the ONYX is designed to offer the highest level of quality at an unbeatable price in its range of high fidelity headphones.
This result underlines the commitment of the engineers on this project to satisfy the most demanding audiophiles.


The internal structure is made of acrylic and it is supported by a skeleton of the same material allowing it to beat at full speed while avoiding the problems associated with sound reverberation.
The ONYX can be matched with all electronic systems and its unique TrueWave technology guarantees a pleasant sound reproduction, without major imperfections.
The TrueWave system is a "3" asymmetrical output cannula topped by a mono–brass bell.
All of that leads to an optimal phase control and a prime magnitude coherence curve.
The Onyx is a hybrid design with a single DD for the bass, two BA drivers for the mids and one BA driver for the highs.
There is no available information for the driver manufacturer but I guess that they still use their proprietary drivers, designed exclusively for Earsonics.
The Onyx has a 3-way HQ impedance corrector crossover and the engineers have decided to use an extra combination of dampers and passive filters to avoid any unwanted phase shifts.
The internals are encapsulated in a 100% metallic shell with a black mat color.


Build quality and looks

Build quality and finish are excellent, the Onyx seems to be durable and tough enough to handle everyday use with ease, Earsonics professional background is clearly distinguishable here.
The look is minimalistic and industrial, very simple with the Earsonics logo engraved at the center of the shells.


Comfort and isolation

The Onyx is bulkier and heavier than the competition but thanks to the anatomically designed inner surface and the extended nozzle, the fit is actually comfortable and stress-free.
The earpieces fit tightly and stay at place but the weight is an issue and becomes quite noticeable after a while.

Each earpiece has two venting slots but they don't affect the sound isolation properties and as such the Onyx has pretty good passive noise attenuation.



The cable is detachable with the 2-pin 0.78mm interface ending in a single ended 3.5mm plug.
It is a four core twisted cable with high purity silver and it is of good build quality with extremely low microphonic noise.
A higher quality balanced cable is available as an extra purchase and while I can understand that Earsonics are trying to keep the selling price as low as possible, I would like to see a balanced cable with an adapter or a modular plug cable included in the scope of the delivery.
Competition is fierce and now almost every earphone at this price point comes with a modular cable or an adapter.



ONYX with is 4C-HR cable
1 Cleaning Tool.
2 pairs of comply tips of different sizes.
2 pairs of silicon monoflange tips of different sizes.
2 pairs of silicon bi-flange tips of different sizes.
1 carrying case made from EarSonics.
1 User manual


Power requirements

The Onyx features a nominal impedance of 16.5Ω with a 122dB/mW of sensitivity so it is ridiculously easy to drive but it is heavily susceptible to noise so make sure to use a DAC/amp of the highest quality.
I have used various sources like the FiiO KA3, Violectric Chronos, Cayin RU6 and iBasso DX240 with the included cable and an aftermarket balanced cable by FiiO.


Sound impressions

Earsonics suggested a burn time of about 20-30 hours and thus I did, stretching it to 100 hours.
While fitting the Onyx you must be careful not to squeeze too deep and block the ear tips.
During the fitting process you are going to notice that there is a driver flex which other than making a clicking sound every time you push the shells into your ears, it doesn't affect the sound properties of the earphone.

The Onyx sounds quite balanced with a mild bass emphasis, combining excellent technical performance with a musical and a warm presentation, a tuning that is rather suitable for all kinds of music and listening habits.

The Onyx is transparent so the DAC/amp and the quality of the listening material should be considered equally important for determining the final audible result.
Onyx is not punishing but not too forgiving either, it will not smooth out bad recordings which nonetheless can be enjoyed as long as you don't use a very revealing or forward-sounding source.

Sub bass extension is great, it can cover all acoustic instruments with ease while at the same time it is powerful enough to offer plenty of excitement with electronic music without clouding the rest of the frequencies.
The bass is boosted then gently downsloping without giving a pronounced mid - bass hump.
It mostly sounds clear, layered and resolving without affecting mid - range clarity and presence.
The bass stays most of the time controlled and tight, not too slow, recovery is natural but there are quite a few instances that it can sound hollow and boomy.
With simpler one note or pizzicato bass tunes it is good but switching to faster moving and multi-layered bass instruments, then you are going to notice a certain lack of control and a droning effect that gets quite noticeable in symphonic works.


Texture is a nice compromise between being visceral and lean, it sounds quite full and at the same time crispy and well defined, you are not going to miss a single note even at heavily populated bass lines.
The sound is contrasted and muscular, timing is good and the Onyx is not a slouch when it comes to sudden dynamic swings, presenting them with authority and power.

Mid range is crystal clear and well projected with tons of layering and the finest articulation.
Timbre is more or less natural but there is an upper - mid emphasis that is leading to a mildly forward presentation which favors certain tunes.
You can also hear some sharper edges here and there which have an extra bite and can grow into shouting notes.
There is plenty of harmonic wealth and abundance of emotions, voices and instruments sound engaging, full bodied and weighty while the texture is well sculptured with a naturally fading relief.
The mid-range cohesiveness is satisfying and well aligned with the upper bass while smoothly leading to the lower treble.
The Onyx is not strictly a mid - centric earphone but you can certainly tell that the mids sound richer and attract the listener's attention, especially with female voices as in the following album.


Treble should be considered rather smooth, well controlled and fatigue free yet not lacking in energy and agility.
Open and spacious, it doesn't sound muted, it is brightly lit, crystal clear and can dive quite deep into the recording to offer some excellent detail retrieval without becoming analytical.
Timbre is mostly natural but you can't fail to notice an extra shimmering effect and a metallic tone color which is not piercing but it has some traces of acidity that corrupt the sound.
Fading is on the faster side but thankfully not too rushed, instruments are heard naturally, although they tend to lose some of their weight when compared with their lower pitched siblings.


The Onyx is top notch when it comes to instrument positioning with accurate imaging and excellent panning in the horizontal axis but it is not so competent when it comes to depth layering.
The soundstage is well extended with plenty of air, never becoming congested even with large symphonic works while it gets easily adapted to the size of the ensemble, always sounding proportional.

In the end

The Earsonics Onyx is an excellent sounding earphone and a step up from the Corsa.
It is not perfect but a few issues here and there can't spoil the otherwise great performance, making the Onyx a solid choice and one of the most enjoyable earphones in the mid price category.

Test playlist

Copyright - Laskis Petros 2022.
Last edited:
Yeah! Front Page!
You know what they say... 2-pin 4 the win! 👍 :)

What do you use for doing burn-ins? Do you use that 6-port burn-in device on AE, with a custom countdown or count-up timer to keep track?
I have a DAC/amp with a streamer running Tidal.
I plug in the headphone and forget it about a week.


Headphoneus Supremus
All Thriller No Filler
Pros: Bass, overall tuning, value, build quality, cable
Cons: only 2 sizes of eartips included
DSC03454 (2).JPG

I received the Onyx without any paperwork or literature so there was no indication as to the driver configuration and I had to leave it up to my ears. The mystery was quickly solved though as I inserted the right shell and heard the telltale driver flex of a dynamic driver. I have small ear canals and experience drive flex with practically all DD equipped IEMs. This would soon prove irrelevant; as soon as I listened to the first track there was no doubt I was listening to DD bass. My past experiences with Earsonics have been with their all-BA models so this was definitely a revelation.

DISCLAIMER - The IEMs were provided by Earsonics for review purposes, all they asked in return was for my honest review. Thank you to @ThioB3 & the team at Project Onyx.

All listening was done on the FiiO M15 on HIGH GAIN w/volume set at 40 using the STOCK 3.5mm CABLE w/the stock MEDIUM silicone ear tips. I gave the IEMs 60+ hours of burn-in out of the box just to eliminate this as a factor. Forgive the lack of pics, the memory card slot on my computer was being finicky as I was preparing to upload them, but I will be updating with pic as soon I can find a card reader. I don't normally write reviews, but prefer to share impressions when I can so this will not be a technical review, but more of an extended impressions post. As such, I consider this review to be a continuing work in progress and will be updating it as I continue to enjoy the Onyx.

I tend to skip this portion when reading reviews. Once I’ve opened up the package it goes on a shelf or cabinet never to be seen again unless I decide to part with the IEM. As long the IEM ships with a decent cable I am happy and the included stock cable is a pretty good quality cable. No microphonics, soft & ergonomic with pre-molded ear loops. More companies seem to be including aftermarket ear tips, but given how Earsonics wanted to keep everything in-house to minimize costs the exclusion of said tips is understandable. I do wish they included size S tips though as they’ve only included size M&L (silicone, double flange, foam).

Regarding the cable, I chose to use the stock single ended cable for the review. Although I do have upgrade cables and tend to do most of my listening in balanced mode, I wanted to review Onyx as-is, out of the box. The benefits of switching to balanced mode (when implemented well) are well known, but I believe including a balanced cable would add to the overall costs & respect that Earsonics has tried to keep costs down for all parties without compromising on sound quality. With that said, I did try out a few cables and found that Onyx did respond to cable swaps, YMMV & all that.

DSC03472 (2).JPG

FIT - I won't comment too much on fit as I feel it is highly subjective. Whether you have small or large ears, there are many other factors such as shape, curves & angles that also come into play. I have small(er) ears & small(ish) ear canals & USUALLY have fit issues with larger IEMs, but had no issues with Onyx.

BUILD - Onyx is built like a tank. Some may find the weight an issue, but I had no issues during long listening sessions or while using them on my commute.

DSC03478 (2).JPG
DSC03479 (2).JPG
DSC03481 (2).JPG

Bass is well controlled and provides a solid base for the IEMs overall warm sound. The DD provides just the right amount of slam and bass is controlled and never overemphasized, without any bleed or bloat. Onyx has more of a sub-bass emphasis. Bass extends deep with a nice sub-bass rumble and provides enough thump that it won’t be mistaken for anything other than dynamic driver bass. Not necessarily sub-basement depth as per the likes of Empire Ears’ W9/W9+ driver, but substantial enough & deep enough to satisfy the majority of us not named Gollum.

Midrange is warm and musical. Vocals are enveloping & intimate. Like the bass, vocals are textured. Whether it’s raspy, breathy or vibrato, Onyx is able to capture it. Staging isn’t the widest, but instruments are easy to place within the space. For live music I did enjoy Onyx more with more intimate & acoustic performances. With larger stages & orchestral performances some of the details can get a little lost within the narrow(er) soundstage.

Treble is smooth without any hint of harshness. Not the most detailed as it is slightly smooth at the upper end, but still exhibits a fair amount of sparkle and provides sufficient air. It never sounds artificial or exhibits any of that "plasticky BA timbre". I am somewhat of a treble-head & can withstand sharp highs up to levels most would consider to be jamming ice picks into your ears, but found no reason to believe the treble on Onyx would tickle these sensitivities.

Campfire Audio Mammoth ($549)
Mammoth is less balanced with a deeper v-shaped signature. Soundstage is slightly wider on Mammoth, but the treble paired with the more recessed mids gives Mammoth an overall brighter sound. Vocals on Mammoth are clean, but are leaner with less body and texture. Bass on Mammoth doesn’t reach as deep as Onyx.

Meze Rai Penta ($1099 - forthcoming)

Onyx offers a consumer friendly sound, but will also satisfy the audiophile looking for a nice balance of resolution & musicality. It's not a detail monster & some may wish for a little more height & treble energy, but for the price the Onyx won't leave many wanting. The bass is definitely the star of the show and it provides a healthy dose of slam & rumble, but it's the overall tuning that makes the Onyx so easy to listen to. I listen to a wide variety of music and during one particular session I rotated through a variety of genres without experiencing any fatigue. There is often a tendency with higher-priced IEMs to want to break down the price vs performance, but with the Onyx I'm able to forget about that and just enjoy the music.

DSC03442 (2).JPG
DSC03465 (2).JPG
DSC03467 (2).JPG
DSC03469 (2).JPG
DSC03484 (2).JPG

SOURCE - FiiO M15 on High Gain, volume level 40
TEST TRACKS (16-bit & 24-bit FLAC)
Agnes Obel - Dorian, Myopia, Roscian, The Curse
Ali Gatie - It's You
Armin van Buren - This Is What It Feels Like
Atticus Ross - Panoramic
Augustana - Boston (Live), Fire (Live)
Bill Conti - The Thomas Crown Affair
Billie Eilish - Bad Guy, Bury A Friend, Getting Older
Bloc Party - Banquet, Mercury (Herve Remix), Signs, Signs (Armand Van Helden Remix)
Chase & Status - All Goes Wrong, NRG
Claire - Broken Promised Land
Daft Punk - Tron Legacy
Depeche Mode - 101
Gang of Youths - Achilles Come Down
Hozier - Arsonist's Lullaby, Take Me To Church
Ingrid Andress - More Hearts Than Mine
Jhene Aiko - Bed Peace, The Worst
John Legend - Let's Get Lifted
John Murphy - Sunshine Soundtrack
Jonsi - Go Do, Tornado
Kanye West - Black Skinhead, Jesus Walks, Mercy, No Church In The Wild
Kings Of Leon - Waste A Moment
Linkin Park - Cure for the Itch, In Pieces, Nobody's Listening, Shadow of the Day
London Grammar - Hey Now, Metal & Dust
Lorde - Bravado, Ribs
Major Lazer - Lean On
Miike Snow - Cult Logic, Silvia
New Order - Bizarre Love Triangle, Blue Monday, Ceremony, Temptation
Nicholas Britell - Strings+808+Beat, Succession End Title Theme Piano and Cello Variation
Nina Simone - Feeling Good, Sinnerman
Raye Zaragoza - Crazy Eyes
Regina Spector - Us
Sky Barbarick - Paper Legs
The Chemical Brothers - Wide Open
The Cinematic Orchestra - Arrival of the Birds
The Lumineers - Cleopatra, Ophelia
The Naked And Famous - Higher, Punching In A Dream, Young Blood
The Sounds - Goodnight Freddy
The xx - I Dare You, Intro, VCR
Thirty Seconds to Mars - Alibi, Bright Lights, City of Angels, Do Or Die, Hurricane
Tinashe - Party Favors
Wael Elhalaby - Smooth Sailing
Yiruma - River Flows In You
Yo-Yo Ma - Bach Cello Suites
Last edited:


Headphoneus Supremus
Earsonics ONYX
Pros: Warm, inoffensive tuning
Overall resolution
Imaging and layering
Rock-solid build quality
Cons: Some people might find the shells heavy
Limited included accessories
No lip on the nozzle
Earsonics ONYX review featured_2

Earsonics is a French IEM manufacturer with over 20 years of experience in the audio field. In this review, I’m checking out the Earsonics ONYX earphones. The ONYX is a hybrid quad-driver IEM with 1 dynamic driver and three balanced armature drivers. It retails for 490€ (approximately US$533).

Disclaimer: This sample was provided by Earsonics for the purpose of an honest review. All observations and opinions here are my own based on my experience with the product.

Earsonics ONYX​


  • Sensitivity: 122 dB/mW.
  • Frequency Response: 10 Hz -20 kHz.
  • Impedance: 16.5 ohms.
  • Driver: 4 drivers (1DD+3BA) with 3 way HQ impedance corrector crossover.
Box front
Unboxing experience

Package and Accessories​

The ONYX comes in an unassuming, utilitarian matte black box. Inside the box, you’ll find the Earsonics ONYX, a detachable 4-wire silver cable, 2x pairs of single-flange silicone eartips, 2x pairs of double-flanged silicone eartips, 2x pairs of foam eartips, a cleaning tool and a carrying case.

What's in the box
Earsonics ONYX design


In the age of flashy, colourful 3D-printed resin shells that we live in, I was pleasantly surprised when I first laid my eyes on the ONYX. Crafted from anodized zinc and magnesium alloy with a matte black finish, the ONYX looks something akin to a Northrop Grumman B-2 Spirit (stealth bomber).

ONYX’s contoured shells are largely unadorned except for an ES logo on the faceplates and some grooves carved into the inner side. On the top of the earpieces are standard slightly recessed 0.78mm sockets.

The nozzle diameter is slightly narrower than average. This and the fact that there’s no lip on the nozzles means that some third-party eartips fit loosely. I’ve had to fish orphaned eartips from my ears more than once as a result.

The shells are heavier than your average IEM. It doesn’t bother me in the least but some people may find it an issue. ONYX fits great in my ears, despite the shells being somewhat large. I can wear these comfortably for hours on end.

Earsonics ONYX with xDuoo Link2 Bal and iPhone

The passive noise isolation is excellent, making ONYX great for blocking outside noises. There’s virtually no noise leak either so this IEM is ideal for commuting.

Internally, ONYX houses Earsonics’ Acrylic Heart® technology which enables precise driver alignment for optimal phase control. The single dynamic driver and 3 balanced armature drivers are positioned within the heart which resides in the acoustic chamber.

Included in the box is a high-quality 4-core silver cable. The cable handles well and feels robust. It doesn’t have any significant microphonics (cable noise) and is not prone to tangling.

ONYX with Soundaware M2Pro


Gear used for testing includes the Cayin RU6, Soundaware M2Pro and iBasso DX120.

ONYX has a warm, musical presentation. It has elevated bass, full-bodied mids and an inoffensive treble. I’d say it has a safe tuning but one with strong technical capabilities. It’s a refreshing change from the recent slew of Harman target tuned IEMs. It doesn’t need extra amplification or a fancy source.

Earsonics ONYX frequency response graph
Earsonics ONYX frequency response.


ONYX gets warmth from its elevated bass. The bass lays down a velvety depth as a foundation for the entire spectrum and is unapologetically boosted north of neutral. There’s grit in the bass too, providing texture and layers in abundance.
With its medium-paced attack and fast decay, ONYX’s bass is rounded and natural yet nimble at the same time. The density of the alloy shells prevents any unruly distortion or resonance resulting in excellent control.

Sub-bass notes dig deep without blanketing the sound or bleeding into the other bands. It not only rounds out the lovely mid-bass but also adds groove and authority to the sound.


One of the challenges of tuning a warm IEM is maintaining clarity and detail in the midrange. ONYX rises to the challenge with aplomb; the mids are energetic, detailed and nuanced.

The transition from the bass to the lower mids is done just right, clearly separating male vocals and instruments while maintaining overall cohesiveness. There’s a clarity and spaciousness in the midrange belying the sense of warmth and musicality that ONYX delivers. Despite the elevated bass, vocals and the midrange, in general, are upfront and engaging.


It’s the treble tuning that does a lot of the heavy lifting when it comes to ONYX’s sound. On one hand, the treble counterbalances the fullness of the bass and brings clarity and detail to the midrange. On the other hand, the treble isn’t sibilant and is smooth enough for extended listening without fatigue.

There’s plenty of detail and energy in the highs for precision and excitement respectively. It’s smooth enough for a daily driver yet is crisp and intricate enough for more serious listening when desired.

Soundstage and Technicalities​

Some of my favourite aspects of ONYX’s sound are the layering and placement. Despite its warm, musical nature ONYX has excellent resolution and instrument separation. As a result, the soundstage is uncluttered and organized, clearly defining the centre image from surrounding sounds.


FiiO FH7 ($449)​


Earsonics ONYX (red) vs FiiO FH7 (grey).

The FiiO FH7 (review here) is a Penta-driver IEM with a 1DD+4BA configuration. FH7’s presentation is more aggressive and very upfront in terms of staging. ONYX is smoother and more easygoing.

The FH7 bass is faster but leaner. It has a cleaner leading edge on bass notes compared to the ONYX’s more rounded ones. The midrange on the FH7 is very forward – the overall sound signature is very linear. On the other hand, ONYX has more of a traditional V-shaped sound signature.

FH7’s lifted upper midrange can get a bit shouty at higher volume. Similarly, the treble on the FH7 is somewhat aggressive and can be strident. The ONYX has a smoother top end but is not as resolving when it comes to micro-details.

The FH7 is an IEM that some people find aggressive and tiring. In comparison, I can easily listen to the ONYX all day thanks to its warmer tone and rounder treble notes.

DUNU Studio SA6 ($549)​


Earsonics ONYX (red) vs DUNU Studio SA6 (grey).

The DUNU Studio SA6 (review here) is a great example of how good an all BA IEM can sound. While the Studio SA6 is more tonally accurate and detailed, ONYX sounds more natural and forgiving.

The SA6 immediately sounds brighter than ONYX. It has less bass quantity, weight and impact. ONYX, in comparison, has a physical bass that you can feel and gives the sound an underlying warmth.

Mids are more forward and have more clarity on the SA6. The DUNU’s mids are clean and transparent while ONYX has added note weight making it more inviting albeit less detailed. Vocals on the SA6 are more articulate and really come to the forefront.

The Studio SA6 has a similar treble timbre as the ONYX but because of its leaner bass, it sounds more upfront. The DUNU is the more accurate sounding IEM but the ONYX has a warmer and more pleasing tonality.

SA6 has a wider soundstage but ONYX has superior layers of depth in front of the listener. Both IEMs have excellent resolution and instrument separation.

Closeup of the faceplate


The Earsonics ONYX is a refreshing change from what is becoming the status quo in ChiFi IEM tuning – the pursuit of the Harman curve with as little deviation as possible. Instead, ONYX is musical and fun and not afraid to throw in a dose of extra bass.

What I really like about the Earsonics ONYX is its warm, melodic presentation intertwined with strong technical performance. The fact that it’s built like a tank and dressed like a ninja only makes me like it even more. Recommended.


Reviewer: Audio Rabbit Hole
Pros: Bass quality & quantity
Coherent signature
Great for long listening sessions
Cons: Heavy in ear
EarSonics ONYX

EarSonics StorePurchase ONYX

A Little Technical Stuff:


  • Sensitivity: 122 dB / mW
  • Frequency response: 10 Hz -20 kHz
  • DCR: 16,5 ohms
  • Driver: 4 drivers(DD/BA) 1X dynamic bass, 2X balanced medium, 1X balanced treble with 3-way HQ impedance corrector
-MRSP: Universal fit 590 euros(inside EU incl. VAT)/490 euros(Outside EU no VAT)

EarSonics is a French company that came into existence in 2005. The company originator is Franck Lopez, a bass player. The SM 64 was one of the first upper-tier monitors that lured me into this audio rabbit hole. Between Westone UM3X and EarSonics SM 64, I cycled through a few models of IEMs between these two companies as I discovered the hobby many moons ago.

Please look at my Head-Fi profile to see all of the IEMs I have owned from EarSonics as they are too numerous to list.

I wish for simpler times in this hobby again where spending $350-$500 was elite class. Unfortunately, some of the IEMs I owned are pushing the limits of $7000. I remember purchasing JH Audio Layla and sweating as I hit the “complete purchase” button. Now the Layla pricing is refreshing.

The return to value and quality with an IEM like ONYX is refreshing.

Companies such as EarSonics spend money developing new technology, whether in build quality or sound technology, which is good for the hobby.


Unfortunately, as the ChiFi market grows, many companies that have been on the edge of R&D like EarSonics feel the pinch.

ChiFi puts a lovely façade on their product and sells it cheaper because they didn’t need to spend money on R&D, as other companies have already done. Not to mention the labor costs are very low relative to other countries.

The last EarSonics review I penned was for the Grace Platinum, their TOTL release. I like the Grace Platinum a lot, and you can read that review here; Grace Platinum.

I will also reference the EarSonics Stark during this review, and that review is here EarSonics Stark.

I was aware that the ONYX was in development for quite a while. However, like the other reviewers, I was not informed of any details, specs, or otherwise.

Similarly, I have been part of a blind review when Custom Art invited 10 of the “best reviewers” worldwide to participate. I know all of the reviewers during that blind review were surprised when they revealed the specs. This review has the same results; the specs and price points are the biggest surprises.

EarSonics involved a more representative cross-section of consumers in this blind review, not just the regular reviewers or fans of the brand.

I feel this type of review is a good idea. It eliminates bias toward the specs and pricing tier.

Once I saw the ONYX, its build and design were familiar and reminiscent of the EarSonics build over the last couple of years.

I was hoping for a sound signature between the Stark and the Grace, and ONYX delivered on that hope.

The Stark was a bass showcase release; it is evident that bass is its focus. At the same time, the ONYX has stellar bass quality with more forward upper mids and inoffensive treble. The Grace was more detailed than ONYX, but Grace Platinum can have an upper mid focus which can be more fatiguing for longer listens.

A Little Marketing Hype from their site, grammar aside:



The Onyx concept is born in the confinement context.

The team of enthusiasts engineers in charge of its development wondered what could be the best earphone that would meet the current requirement of audiophile public.

What started out as a concept turned into a real project.

The ONYX was born.


This team of passionated, the heart of the ONYX project, designed it based on the knowledge and know-how used in the Earsonics laboratories.

After several months of work, the first plans for the ONYX were here and with them the beginnings of an exceptional earphone.

To develop the ONYX, using the best materials was the leitmotif of the team.


When developing it, the engineering team used the best.

Thus, the ONYX is based, among other things, on the latest generation of 3D acrylic core used for the ONYX Platinum, Earsonics flagship.


The specific inclination of the ONYX body and cannula is the result of many years of research guaranteeing a comfortable fit and better insulation.



The use of "2 pins" is still today the safest and most efficient method to connect your in-ear headphones to their cable.


Entirely handcrafted in our laboratories, the ONYX is designed to offer the highest level of quality at an unbeatable price in its range of high fidelity headphones.

This result underlines the commitment of the engineers on this project to satisfy the most demanding audiophiles.


Through an approach aimed by a new sound bias, the ONYX is a 100% exclusive earphone with the dynamism, precision and balance primary characteristics.


At all sound volume ranges, you benefit from the entire sound spectrum thanks to the ONYX's ability to transcribe the dynamics. Its extension in the bass and the depth of the sound field also contribute to this dynamic presentation of the ONYX.


Rigorous care has been taken in the sound filtering of the ONYX. Its electronic circuit resulting from professional sound processing technologies, executes the information with precision and optimal control of the phase before feeding the transducers which deliver the sound.


Thanks to a skilful proportioning in the sound processing, the ONYX maintains a perfect balance and a faithful transcription of the timbres at all listening volumes.


This is the conclusion given by our engineers: its sensitivity-impedance couple allows the ONYX to work with all audio peripherals (sedentary DAC, DAP, walkmans, mobiles, etc.).


The ONYX proved to be able to maintain balance and sonic rigor at high listening levels during our various tests. Triggering emotions, its signature designed in collaboration with Earsonics ensures a unique rendering.



  • ONYX with is 4C-HR cable
  • 1 Cleaning Tool.
  • 2 pairs of Comply tips of different sizes.
  • 2 pairs of silicon mono flange tips of various sizes.
  • 2 pairs of silicon bi-flange tips of different sizes.
  • 1 carrying case made from EarSonics.
  • 1 User manual.
Unboxing and Accessories:


The ONYX arrives in a black box; ONYX colored, to be more precise, with the ES name and initials in the lower right corner. Once you flip open the lid, you see the monitors and the standard EarSonics zippered carry case. There is also a cardboard sleeve apparent in the box.

EarSonics carry cases are the best portable carry solution for my usage. I have used them for years to transport my IEMs when traveling for work or even just for storage, so simple yet convenient.


Once you open the zippered case, the ONYX greets you. Already cabled with a 2-pin non-balanced HR 4C Silver cable and a business-style card with the individual's name that handcrafted the IEM. A balanced cable would be a nice inclusion. However, I understand entirely that this would increase the price. Offering a bundle discount to include both cables might be a suggestion.


Inside the cardboard sleeve are the cleaning tool and the various eartips. I find it challenging to start criticizing EarSonics for the quality of the cable because I complained for years about them using the Plastics One cable. I am glad they have upgraded the offering, but it feels like a cheaply made upgrade.

Also, the ear tip offering is scant. Certainly could be more included.


I have learned through trial and error that I cannot ever achieve a solid seal with EarSonics stock tips and always reach for the Final E style tips. They always provide me with excellent seal and sound quality for EarSonics. The limited options of included ear tips are no big deal to me, but it might be to someone that doesn’t have a selection of tips at home.

Build Quality and Fit:

ONYX feels like the build could withstand a military attack, solid. That said, with the solid form comes additional weight. As a result, it is a heavy IEM.

The ONYX is well-built like the last 3 to 4 releases for EarSonics, with a metal outer shell. However, as I said, the excellent build and what feels to be a durable IEM has a downside; its weight might annoy you. The weight isn’t a deal-breaker, but I find myself fiddling with these while in my ear.


Size-wise, if you have small ears, there could be some fit issues. However, I have large earholes, and the ONYX does not give me any problems, except for weight. The shape of the monitor seems to work well.

The sound signature is so addictive that the slight trade-off of an occasional in-ear adjustment is worth it.

Review Setup:

I paired the ONYX with the Astell & Kern SP2Kt on Hybrid mode. If interested in the SP2Kt, I did a drive-by(mini-review) of the SP2Kt here Sp2000t.

Cable-wise, I listened using the stock 3.5mm cable and the EA EVO with a 4.4mm balanced plug. When using the EVO cable, the dynamics of the sound are improved. One of the most notable improvements is that the already stellar staging is even more defined. In addition, the ONYX sounds more dynamically charged on all fronts than with the stock cable. I am not reviewing the EVO cable; I only wanted to mention it.


My sample music consisted of 320kb, FLAC, 24bit, and streaming Tidal and Amazon Music HD.

For eartips, I found that the Final E tips gave me the best sound quality.

Moving on to the sound section….

It would be bold and capable if I were to characterize ONYX in a few words. The ONYX is a little bit of a marriage between the Grace Platinum and the Stark. The resolution and air separate it from the Stark, and the bass quantity separates it from the Grace Platinum.

ONYX is meaty, robust, and capable of providing enjoyment when listening to all genres of music.

Staging and imaging strike above similarly priced IEMs. It is not a super-wide stage, but it is wider than a square, with the depth providing a better impression than its width. It is not holographic, but the depth is apparent. I wouldn’t expect a holographic listen at this price point. However, it is certainly not the most intimate and closed-in IEM I have heard. The accuracy in its staging is also very impressive given the price. Realism without an exaggerated stage is how I would summarize.


ONYX is bass bold, like the Stark, but different. The bass quality is better in the ONYX, and the overall signature has much more air. ONYX’s tuning allows for plenty of bass quantity while respecting the rest of the signature; this results from excellent sound engineering.

The bass has a snappier decay, so the notes don’t linger as long as they do with the Stark. Less decay allows for more resolution and enables you to distinguish the layers in the bass frequencies.

Mid-bass is clean, precise, and does not interfere with the mid-range. Although I am trying to draw on my memory bank to recall a better-sounding mid-bass, the ONYX has to be one of the best. The control relative to other bass-focused IEMs is spectacular.

The Empire Ears fabled Legend X is an IEM that comes to mind when listening to the ONYX. The ONYX and X share some bass characteristics. Slamming DD bass is on the menu for both. Both the X and the ONYX have an immersive feel. However, I may say the ONYX has less bloom and slightly more definition in its bass and a better presence in the upper mid and lower treble frequency. ONYX has an overall airier feel when listening.


When you know that the owner of EarSonics, Franck, is a bassist himself, it connects the dots as to the focus toward quality and quantity bass in ONYX. Very well done!

The mid-range provides an excellent portrayal of vocals. That was one area that immediately stood out to me when I was critical and pleasure listening. The lower mids showcase male vocals, and the upper mids female. Next to the bass, vocals are the star of the show.

I do hear some lift in the upper mids, but nowhere near the level of Grace Platinum; it is more of a gradual rise. I read criticism of some of today's more upper mid-focused IEMs as too forward or too sharp and fatiguing. However, while there is presence in that range, I do not find it offensive, but rather assisting in balancing what could be a bassy signature. Likewise, the mids create a balanced listen.

Details are present, but nothing fatiguing. However, suppose you are into micro details. In that case, you may wish to look in another direction because that is not the strong suit of the ONYX.

To characterize the treble, one would have to say it is smooth with average extension. There is no harshness, no sharp tones, and good extension relative to the coherency of the signature. Again, you will not hear much twinkling to the fringe, but to repeat, it adds balance to the full signature.

The treble does roll-off, but it is my preferred signature. There is less sparkle than Grace Platinum more than Stark or Legend X. If bright treble is your thing, there is probably not enough treble presence for you. It is essential when pleasure listening to take in the entire ambiance and not focus on one frequency.

The treble is satisfying in my pleasure listening sessions and is undoubtedly a part of forming one excellent coherent package.

You might want to own this IEM if:

+ You want excellent bass, both in quality and quantity

+ You prefer a smooth, balanced, non-offensive treble

+ You prefer a sound that is bold and capable

+ You like a coherent stage with an incredible portrayal of vocals

In Closing

It is undoubtedly an honor and a pleasure to be part of the review group. The ONYX is one fantastic listen. In this closing, I am fighting not to overuse the phrase strike above its price point, but that is what the ONYX does.

The price inclusive of VAT for purchase within EU is 590 euros and without VAT 490 euros outside EU. I know it can be confusing to see prices quoted in some reviews, but this is the discrepancy in pricing.

There are a few comparisons to other IEMs sprinkled throughout the review. However, everything compared to ONYX costs quite a bit more. Knowing I am comparing ONYX to much higher-priced IEMs should speak for itself.


The bass is near the top of the list of the IEMs, both in quality and quantity. Of course, I am biased towards DD bass, but in the ONYX, the execution of DD bass is top-notch.

ONYX staging is accurate, and the Onyx strikes above its price point in this area. Using the Snarky Puppy Live From Richmond, a concert I attended, as my validation tool.

The treble is smooth, it is not the most sparkly treble, but the treble does blend very well with the full signature. However, this IEM probably won’t please you if you are a treble head.

One concern you can encounter with hybrid (multi-driver type) designs can be coherency. I can assure you there are no coherency issues with the ONYX.

I found this IEM to work well with all genres of music. For example, the speed and decay of the bass work well with jazz, and the quantity sometimes makes bass lighter genres such as classic rock sound spectacular.

The build quality is impeccable. Sturdy and durable but can be heavy in the ear. Whether the added weight gives you concern will be personal.

In closing, the ONYX is a homerun. Its sound and price captivate. When I listen for pleasure, my two current go-to’s are the Empire Ears EVO and the ONYX.
Last edited:
The ONYX is a homerun! I totally agree with that statement and enjoyed (incl. some interesting comparisons) reading your review :)
Thank you! I appreciate that.
  • Like
Reactions: 554130


Headphoneus Supremus
Pros: Built like a tank, individually hand-made
Easy to drive
Above average isolation
Excellent soundstage
Non fatiguing, warm tuning
Good coherency (considering it is a hybrid)
Big bass for bass lovers
Cons: Heavy shells
Mid-bass bleed
Not the most detailed

I would like to thank Thibault from Earsonics for providing this review unit. It can be gotten here: https://www.earsonics.com/store/produit/onyx/

Unit was burnt-in for 100+ hours.



The Earsonics Onyx is a musical, warm and bassy V-shaped IEM with excellent build. The Onyx excels at soundstage, and has surprisingly good coherency, considering it is a hybrid set-up.

Some small nitpicks would be a heavy and large shell (though comfort is decent), and there's some mid-bass bleed, which gives warmth to the lower mids (this can be a hate-it or love-it kind of thing).

The Onyx would be a good set for bass-lovers who prefer a non-fatiguing and darker tuning, with the holographic soundstage being a particular highlight.

  • Driver configuration: 1 Dynamic Driver + 3 Balanced Armature Drivers with 3-way HQ filter with impedance correction​
  • Frequency response: 10 Hz – 20000Hz​
  • Impedance: 16.5 Ohms​
  • Sensitivity: 122 dB/mW​
  • Cable: 2-pin 0.78 mm 3.5 mm​
  • Price: Inside EU 590€ (incl. VAT); Outside EU 490€ (without VAT)​


Other than the IEM itself, the Onyx packaging comes with:

- 2 pairs of silicone tips
- 2 pairs of double-flange tips
- 2 pairs of foam tips
- Cable
- Semi-rigid carrying case with a zipper
- Cleaning brush


The accessories provided here are quite adequate for most consumers, everything is quite usable out-of-the-box, with no need to source for aftermarket gear.

Eartips are as personal as shoes; my general findings are that the foam tips provide the best isolation, but tend to dampen the highs (and the Onyx already does not have the most extended treble to begin with). The double-flange tips also give good isolation, but may pose a comfort issue for some. I found the best comfort with the silicone tips, and they were my most used of the eartips.


The stock cable is a 4-core high purity silver cable. It is quite supple and has minimal microphonics. I like that it is a 2-pin type connector, as MMCX connectors tend to have a shorter lifespan with frequent cable changes. A chin cinch is a nice addition to provide added stability.

For the purposes of this review, the stock silicone tips and stock cable were used. No aftermarket additions were used so as not to add confounders to the sound.


Each individual Onyx is hand-made in France. The shells are furnished of metal and they are literally built like a tank. Shell quality is top-notch and there shouldn't be any worries with dropping them! I daresay they are one of the sturdiest IEMs I've held in my IEM journey of the past 2 decades. The shell size is quite large and heavy, but surprisingly, comfort is quite good for the large size, and I have average sized ears.


I didn’t find any driver flex for myself (but YMMV once more as this is somewhat dependent on ear anatomy and types of ear tips used).

Unfortunately there is no filter/wax guard at the nozzle, so potentially ear wax and debris can drop inside the IEM itself. So, best to do routine cleaning and checking of the nozzle with the provided cleaning brush.


Isolation is above average, the Onyx can definitely be used in noisy places without an issue. They passed my subway test too with flying colours.


I tested the Onxy with:
- Khadas Tone Board -> Schiit Asgard 3 amp
- Khadas Tone Board -> Topping L30 amp
- Sony Walkman NW A-55 DAP (Walkman One WM1Z Plus v2 Mod)
- Sony Walkman NW A-55 DAP (Walkman One Neutral Mod)
- ESS ES9280C PRO DAC/AMP dongle
- IKKO Zerda ITM01 dongle
- Tempotec Sonata HD Pro dongle (BHD firmware)
- Smartphone

The Onyx is easy to drive, amping is not particularly necessary. In view of the warm tuning with big bass, the Onyx synergizes better with analytical and brighter/neutral sources. Pairing the Onyx with warm and analogue sources may give too much low end. YMMV.


The Onyx sports a warm V-shaped tuning with big bass.

Earsonics Onyx.jpg

Earsonics Onyx graph via IEC711 compliant coupler. There is an artefact resonance peak at 8/9 kHz.

Considering the Onyx is a hybrid, it is surprisingly coherent with decent timbre for vocals and acoustic instruments.

Soundstage is a real highlight on this set. Depth and height of soundstage are excellent, width of soundstage is above average and this gives an almost holographic presentation for music. The large shells and depressed mids probably have a part to play with the large soundstage, and the Onyx actually may beat some of my earbuds (which are transducers outside the ear canal) in soundstage depth. Imaging, layering and instrument separation are quite decent, though micro-details are not a strong suit for the Onyx, partly due to a treble that veers towards a darker side.

The Onyx is just a level shy of basshead amounts, and is sub-bass focused. Sub-bass rumbles with authority. The mid-bass is on the slower side and bleeds a bit, though texturing of the bass is quite nicely done. Eartips will influence the isolation and hence sub-bass amounts, so do explore with the various provided tips on what suits you sonically (and comfort-wise).

As per the V-shaped tuning, the mid-range is depressed. The lower mids are warmed by the aforementioned mid-bass bleed, adding heft and lushness to this area (may be a pro or con depending on you). The upper mids have a ~10 dB pinna gain and vocals are forwards without being shouty.

Treble rolls off early, and the Onyx is not fatiguing and is safe for our treble-sensitive brethren. There's not much sparkle and air, so trebleheads may need to look elsewhere. Note weight is a bit blunted and well-rounded. This safe treble minimizes sibilance, though at the expense of clarity and micro-details, so pick your poison.



Mangird Xenns Up ($700 USD)

The Xenns Up is another warm bassy set, but it has better bass texturing than the Onyx. However, the Onyx has better soundstage, layering and imaging, with music sounding a bit compressed on the Xenns Up. The Xenns Up has better accessories are are lighter in shell weight. Timbre sounds a more natural on the Onyx.

Audiosense AQ7 ($498 USD)

The AQ7 features a unique tuning: sub-bass and upper mids boost with a rolled-off treble. The AQ7 has better accessories and features a smaller and lighter shell (though surprisingly I found the Onyx more comfortable, as the AQ7 had a concha protrusion that pressed on the ear).

Other than the Onyx being more balanced in tonality, the AQ7 has worse timbral accuracy and sounds artificial for acoustic instruments. The AQ7 has a thinner note weight and a more compressed soundstage and sub-par imaging, but has better micro-details than the Onyx.


In a nutshell, the Earsonics Onyx is a musical, warm and bassy V-shaped set. The Onyx excels at soundstage, and has surprisingly good coherency, considering it is a hybrid set-up. Bass-lovers should look out for this set!

Soundstage is a real highlight on the Onyx, and music can sound holographic at times. There's some mid-bass bleed, which adds warmth to the lower mids, and this can be a like-it or hate-it thing. The non-fatiguing tuning also makes the Onyx suitable for treble-sensitive folk.


Build is stellar, and considering the bigger and heavier shell, comfort is actually quite decent. In addition the Onyx are easy to drive, with no amplification necessary. The Onyx falls in a weird pricing between TOTL and mid-FI IEMs, but I think it has a niche in this market for bass-lovers that want an excellent soundstage with a non-fatiguing sound.
Last edited:


Headphoneus Supremus
Earsonics Onyx: Heavy Hitter Sound, Lightweight Pricing
Pros: Impactful and satisfying bass
Musical and engaging tuning
Fit is great even with large shell
Impressive staging at this price
Cons: None at this price point
A Little About Me

Another year, another review. That’s about how often I review a product, in fact, and the “About Me” piece seems to rotate as equally often it seems. Although what remains consistent is my love for trying new gear and my fond memories of Earsonics across my audio journey. Sure, I’ve tried about 80-90% of the high-end IEM offerings over the last few years, but I only enjoy writing reviews on what really stands out from the rest. Whether it be due to a tuning that resonates with me, bombastic low end to satisfy my bass cravings or an otherwise intriguing feature that puts a smile on my face, there have been a few IEMs over the years that have truly excited me. The Onyx from Earsonics is one of them.

Typically I purchase all of my own gear and as mentioned above, I review what puts a smile on my face (or whatever I have time for). In this instance, I must mention that I received my pair of Onyx IEMs in exchange for my honest opinion. I won’t do anything differently in this review, meaning that I will give my honest, open and unfiltered opinion. Anything to the contrary would be a disservice to the awesome Head-Fi community and not be something I would ever agree to.

My Earsonics Journey

My journey with Earsonics began many years ago when I talked my wife into purchasing the S-EM6 IEMs for me for my birthday. As the saying goes, it was all downhill from there. I believe the S-EM6 was the first IEM to use six drivers and they were leaps and bounds better than anything I had ever heard. They were also what I would have classified as an “insane” amount of money to spend on an IEM at the time, but thank you Massdrop and a wife willing to front the bill in the spirit of an audio addiction birthday present.

I loved the S-EM6 so much that in the coming months/years, I owned the Velvet, S-EM6 V2, the Purple (okay this one was on loan and I barely gave it back), the S-EM9, the Grace, the Stark and the Grace Platinum. As you can see, I’m no stranger to Earsonics and they’ve always been a company I have a soft spot for. Maybe it’s that their head dude is a bass player and always pays special care to that frequency range, or maybe it’s their exceptional customer service in the event that you do need help, or maybe it’s that they fly under the radar on Head-Fi? Either way, I like what they do. So again, special thanks to Earsonics for allowing me the opportunity to review the latest and greatest on offer.


My Setup

I see a lot of discussion about synergy, proper amounts of power and even disagreements over “your source isn’t good enough” type of thing. So, I’ll just lay out the details here about how I’ve listened to these IEMs. My main source is a Ifi iDSD Signature desktop DAC/Amp which can run either solid state or tube output stages. My music feeds through via Tidal “Master” where available, or at least “Hi-Fi” which is basically FLAC files. I would say 80% of my listening is done on this setup and the rest was done on my trusty Cayin N6 Ti DAP, which includes the R2R R01 module. I run Tidal on that DAP as well, so nothing super fancy. During the course of the review, I also obtained a Shanling M9, which I used a few times with Onyx as well.

Worth a quick mention here is that Onyx only came with a 3.5mm cable and given that all of my sources are 4.4mm balanced, I thought it appropriate to use the 4.4mm cable that came with my Grace Platinum. This is still an Earsonics-branded cable and I felt it was best to utilize this rather than 3.5mm because I am so familiar with the 4.4mm sources I have in that output configuration. Sorry for any confusion.

Onyx – Accessories, Fit and Tech

If you’ve purchased an Earsonics IEM in the past, there won’t be any new surprises here as it is a fairly standard offering from Earsonics. Inside the box, you get the IEMs and cable displayed proudly, some tips, a small case, a cleaning cloth and some literature to help you practice your Francais.



If you’ve used the last one or two generations from Earsonics, then the fit will not be any new surprise either. The shells of the IEMs are quite similar to the Stark, Blade and Grace Platinum. The shells are solid metal and built like they could withstand being run over by a car. They’re not super heavy, but definitely feel more substantial than an acrylic IEM. While somewhat large in size, fit for me is spot on and they disappear in my ears (unless it’s cold and then they’re a bit of a wake up call upon insertion). Nozzles are somewhat narrow, though my go-to Final E tips work just fine. It’s hard to comment if the shape of these will bother anyone, but they certainly feel amazing in my ears and I have not reached a point where any pain is felt. Contrast that with something like the Erlkonig where I struggled every step of the way and I am very pleased with how these fit.



The tech inside Onyx is a dynamic driver and three balanced armatures, which is a fairly standard setup. But of course, execution is key and these IEMs use the hardware very well. At 490 euros, they provide an incredible value from a trusted, time-tested manufacturer who builds their IEMs by hand in France and knows how to tune an IEM to use the drivers to their fullest.


General Sound Signature and Characteristics

Before I talk about the sound, I should state that I knew absolutely nothing about Onyx when I agreed to this review. Believe me, I badgered Earsonics repeatedly to understand what I was getting myself into and was kept in the dark the entire time. It reminded me of a quote from the movie “The Departed” where one of the agents states “My theory on Feds is they're like mushrooms. Feed 'em s*** and keep 'em in the dark.” I was the Fed.

So, you can imagine my relief when a package arrived from Earsonics, containing IEMs, that when I placed them in my ears were immediately exciting. They sounded different from any Earsonics I had ever heard before, whether it be a fun hybrid with a dynamic driver or a 10-armature masterpiece like Grace. Less than 10 seconds into my first track, I knew this was some of the best bass I had ever heard with an exciting and musical signature to follow.

Onyx’s signature can be characterized by power. There is a muscular force behind the bass, something that will immediately draw your attention. But while hard-hitting bass-driven IEMs are a dime a dozen, Onyx does it in a way that doesn’t sideline the rest of your music. That massive bass is balanced with incredibly full-sounding instruments and vocals, ringing through with speaker-like physicality. Up top, things are controlled, but adept to keep up with the rest of the frequency band. It’s incredible to hear the power behind Onyx, while also being very capable portraying of the subtleties of the music. Make no mistake that this is a bass monster, but it doesn’t sacrifice anything else. Below, I’ll drill down on the individual components that make up the sound, but the overall signature is that of rambunctious musicality combined with plenty of technical prowess. If I had to attribute the signature to a letter, I would call it a W-shape with a boosted front side of the W and a slight smoothing of upper treble on the tail end of the W. That sounds ridiculous, but in normal terms I would confidently say that the bass is the star of the show with an elevated quantity, followed by thick-but-not-too-thick mids that sit forward enough to keep up with the bass, and then a sparkly treble with a pleasant smoothness at the very top. That really is a mouthful, so let’s get into the specifics.


As mentioned, I think the bass is the star of the show on the Onyx IEMs. Starting with the sub-bass, you get a massive and full impact reaching to great depths and providing an abundant punch if the music calls for it. Extension specifically is very impressive, though not reaching to the very bottom of what humans can hear like something akin of the Legend Evo, but extremely impressive nonetheless. Listening to that clean and massive punch down low leaves nothing wanting, and I cannot get enough of the full, impactful bass presentation. Into the mid-bass, there is a solid and punchy sound on display that is some of the best mid-bass I’ve heard. Nothing is bloated and nothing is bleeding into other frequencies, but instead you get a great physical feel from that dynamic driver that is always in control. It’s very impressive, given the price point, what these IEMs can unlock as far as bass is concerned from many genres of music. Listening to Onyx with my regular music, I’m hearing note tracks in the lower registers that I never paid particular attention to, though with Onyx I find myself immersed. Very, very impressive bass and before Earsonics told me what was inside these IEMs, I swore there were two dynamic drivers. While I don’t have a Legend X anymore, these sure brought that bass slam back from memory.


Earsonics is no stranger to the mids and the Onyx portrays vocals/instruments in a very pleasing fashion. Vocals ring through with authenticity and demand your attention, while not being forward in a way that distracts from the rest of the signature. Again, the bass is quite full and emphasized, but so are the lower mids to where the transition gives a sense of balance. Vocals from both male and female singers are quite textured and energized, giving exciting impact and engagement. These are the opposite of a boring-tuned IEM, especially in the bass and midrange. You won’t miss the subtleties of a vocalist like Adele, yet you’ll undoubtedly enjoy the rasp of Foo Fighters or other rock bands. Mids have always been a strong suite of Earsonics and the Onyx delivers with an above average clarity and presentation of detail. I’ll finish the mids section by saying the tuning is done incredibly well, where there are no harsh peaks into the upper mids that could offend those sensitive to such an emphasis. We have a very linear transition into the upper mids, and perhaps even a slight drop off, that ensures these are an easy listen for hours and nothing comes across as “shouty.” Mids do lean toward intimate, but not closed off in any way. Listening to your favorite singer is such a treat on Onyx.


Treble on the Onyx is delivered in a manner where a wide range of preferences will find it very pleasing. It’s smooth, detailed, natural and won’t produce any harshness. Extension is very good, though these IEMs do not soar into the upper-most registers. Instead, they are tuned to a more relaxed and natural signature that is wonderful for an all-day listen. I always said I wanted the Legend X to have a touch more treble and surprisingly, these deliver that (with comparable bass). I would say the lower treble has a nice density, though still offers precision and speed where needed. Upper treble is smooth and again has a nice roll-off, though I’ve not seen any graphs to confirm.


For the price, I find imaging and resolution to be spectacular. While these may not give an insanely stretched stage like the Oriolus’s Traillii, they sure do provide an incredibly engaging listen thanks in no small part to the high resolution, great separation of instruments and a perpetual sense of clarity in the signature. Stage stretches wide and deep, though it’s more realistic than something like Traillii where it’s completely out of your head. Onyx gives a true to life feel and a believable image of the music you’re enjoying. This area is where I really see Onyx punching above its price class, because it’s difficult to pinpoint what a $3,000 IEM does better in regards to imaging and resolution. While IEMs costing five to 10 times more should offer a much greater quantity of resolution and clarity, the Onyx is just so damn good in this perspective that it highlights the rule of diminishing returns. If I had to put any flaw here, it would be that micro-details are a bit behind top of the line IEMs (but better than anything at this price range I have heard).


A small disclaimer: the Onyx is my least expensive IEM by a significant margin, so if the comparisons seem off-caliber it is because this is all I have. But, thankfully, Onyx punches way above its weight class and therefore I’ve included a few heavy-hitters below that I normally wouldn’t given the cost difference.

Earsonics Grace: I have owned two versions of Earsonics’ Grace (the original and Grace Platinum) and this is their top of the line flagship. While Grace costs over three times what Onyx does, it’s still worth comparing given the value Onyx brings and even a few areas where Onyx really challenges Grace. Starting with the bass, there are major differences here. While Grace has some of the best balanced armature bass I’ve ever heard (coming close to rivaling Oriolus’s Traillii in fact), it is no match for the dynamic driver in the Onyx. Sub bass reach and impact are greater on Onyx, where Grace has a slight roll-off on the deepest of notes. Texture is great on both and once we get into the mid-bass, things equalize a tad although there’s still a lot more physical punch in Onyx. Into the mids is where Grace really shines, with pleasantly textured vocals and energetic instrument reproduction. Grace has a sense of space and air, with Onyx being more intimate and warmer. While stage dimensions are pretty good on Onyx, especially for its price, Grace has a more open and vast stage that stretches further. Imaging precision is strong on both, but Grace has the upper hand in picking out individual nuances given its technical abilities. Up into upper mids and lower treble, Grace has more energy and clarity with a more forward presence. Onyx in contrast, has the easier listen with a smoother tonality and an easy-going almost analogue-like sound. While I don’t think Grace’s treble or upper mids would really bother anyone, Onyx is the safer tuning here with a more relaxed sound. For extension and sparkle up top, again Grace has more energy while Onyx presents has a little less bite. The treble on Onyx is fantastic, with a pleasing tonality and very solid extension, it just has less energy than Grace.


Earsonics Stark: given that the Stark has one dynamic driver and four balanced armatures, I figured this comparison was somewhat apples to apples. While Onyx has one less driver and costs roughly one third the price of Stark, these two are surprisingly even-matched (to me) with several wins going to the Onyx in fact. Starting with the bass, Onyx has a more physical presence with greater impact and punchier dynamics. Stark has a similarly-reaching deep sub-bass, with even a bit more control, but Onyx has this punch that makes you feel like you’re experiencing the music in a more physical sense. Where Stark has a very deep and controlled sub-bass, Onyx has nearly the same sub-bass reach with greater quantity and also a mid-bass that really presents with impact. I don’t know if the difference is just tuning or an entirely different driver, but the Onyx’s bass just has this slamming, toe-tapping quality that brings out bass notes in your music that you never knew were there. Into the mids, Stark is a little leaner where Onyx has a bit more thickness that give vocals a nice feel and more natural tone. Not a huge difference here, but Onyx gives that extra note weight in the vocals and instruments that add to the musicality factor. Stark, alternatively, is a more V-shape tuning with mids that are thinner and more articulate in nature. Different tuning, different focus, but not miles apart here. Up into the treble, I hear the Onyx treble to be more sparkly and also more textured. Oddly enough, I can declare a “win” here for the Onyx because the treble is just so pleasant in nature. Great extension, great sparkle and energy, while never fatiguing. Stark has great treble also, with an airer quality, but given similar extension I think I would rather hear the Onyx treble. Technicalities are pretty similar between the two IEMs and any differences here are likely attributable to the tuning differences. Where Onyx really shines in this comparison is the tonality, and specifically timbre. Onyx just sounds so natural while being super engaging, where Stark has a tonality that is almost a touch artificial in direct comparison. Overall, while I love the Stark, it’s hard to recommend it for nearly three times the price of the Onyx.


Noble Sultan: Since I don’t have a lot of IEMs in the price range of Onyx, I’ve opted to compare to the Noble Sultan which I know and love well. Sultan uses a 10mm dynamic driver, four balanced armature drivers for the mids and two estats for the treble. In overall signature, Onyx is the more musical and warmer flavor, while Sultan has a greater sense of fidelity and extension from top to bottom. In the sub-bass region, Onyx and Sultan are evenly extended. But the weight of Onyx’s bass is heavier, with an increased physicality carrying up into the very-punchy mid-bass while Sultan remains more controlled and a touch cleaner. Lower mids are thicker on the Onyx, while Sultan portrays a more articulate sound. Mids and upper mids are somewhat similar, with Sultan displaying a more clarity-focused presentation and Onyx giving huge, lush mids with an awesome texture to vocals and stringed instruments. Into the treble region, Onyx is the smoother monitor, with Sultan giving a snappier and faster treble, especially into the upper treble. Levels of sparkle are somewhat similar, with an airier sound going to the Sultan. Onyx has a “listen all day” treble that I won’t call relaxed, but rather pleasant and rounded. While both monitors are tuned for musicality, Onyx takes that further and Sultan stays truer to the “HiFi” sound and greater technicalities. But damn is Onyx fun, of course. For stage dimensions, imaging and separation, I would give a slight nod to Sultan, but the Onyx gives a very grand musical presentation with quite impressive stage as well. Also, given the price delta here ($3,000 vs. $600), pretty impressive showing from Onyx even if it cannot keep up technically to the top of the line Noble offering.


Noble K10: ah yes, a true classic and one of the best-known TOTL IEMs on Head-Fi. While K10 started out as a very expensive ($1,500+ was it?) monitor, it has since gone through a few iterations where it could be had for ~$700 on Drop (formerly Massdrop). These IEMs are quite different, with the K10 offering 10 balanced armature drivers and the Onyx of course sporting a dynamic driver and far less balanced armatures. Full disclaimer that the K10 is an IEM I have known and loved for many years, so I was happy to have a friend loan me one for this comparison. Starting with the bass, it is probably unsurprising that the sub-bass reaches deeper and provides more impact on the Onyx. Into the mid-bass, these two are fairly evenly-matched with a nice punch and great thumping musicality. I still think Onyx has a bit more punch, but K10 gives a really fun and punchy presentation that still to this day is one of the best at straddling musicality and clarity. Mids have more precision on the K10, where Onyx gives more texture and weight especially to vocals. K10 has an airy presence in the mids, but I wouldn’t say either is more forward. Up into the treble, K10 is again lighter on its feet where Onyx is natural and a little more dense. With lower treble, K10 has a very precise, responsive character and Onyx is more nuanced, subtle and smooth. With upper treble, I feel like the K10 extends a touch higher, but sparkle levels are similar and it comes down to a tuning preference. K10 provides a little more of a neutral, HiFi sound and Onyx gives a sense of fun that satisfies cravings for musicality.



It’s been a very fun journey with Onyx, and quite a refreshing one given the price these can be acquired for. IEMs seem to be trending upward at an alarming rate, with prices rising into the five digits of US dollars. The concept of diminishing returns applies here and I’m truly impressed with what Onyx bring to the table. Granted, my concept of pricing is also jaded and while most people would balk at paying $500+ for an IEM, I really feel that these bring an insane value to the high-end IEM market for what they deliver. I think Earsonics knew this too, given that they refused to tell anyone the price and demanded that we simply listen to them and write a review.

Earsonics Onyx IEMs knock it out of the park in several areas, including fit, build quality, bass response, tuning/signature and overall musicality. It’s hard to find any fault with these, especially at the price point, and no deficiencies exist that present any roadblocks to a recommendation. They’re not at the level of multi-thousand dollar IEMs as far as technicality goes, but I will put the tuning and enjoyment up there with the best of the best of the best. I simply want to listen to them all the time and the smiles they give me are worth many times their asking price. I have to hand it to Earsonics, because I truly feel they have created a classic here with the Onyx. In fact, I worry that they have priced them too low to be taken seriously! So, it’s probably time they create a “Limited Edition” version and charge three times the price to gain the attention of the more demanding Head-Fi crown :)



  • 382EB3CF-94C0-496C-B597-CA4C6EF0FAAE.JPG
    1.5 MB · Views: 0
  • CAD778C4-C274-496B-A67E-729C292FED8F.JPG
    1.1 MB · Views: 0
  • CAF07533-8BC0-44C9-AECF-FDD7EBBE6D16.JPG
    1.9 MB · Views: 0
  • ED82220A-FD9A-4661-9380-72BA14C9D21C.JPG
    1.5 MB · Views: 0
  • IMG_3124.JPG
    1.5 MB · Views: 0
Great job Collin!
Oh... and please let's also not forget the maybe underrated, but outstanding and visually very important pose contribution of Tucker's reflection in the ONYX box! That cute little dog certainly deserves a treat after such a tough day of 'posing work' :smile:
I paired the Onyx with the Burson Funk for that review, and the duo is quite stunning together. The vibrant sound of the Funk pairs exceptionally well with the sound emanating from the Onyx.

I can’t say it’s a new appreciation, but fondly remembered and embraced.


Headphoneus Supremus
Moonlit Abyss
Pros: Voluminous bass
Durable build
Cons: Bass texture
Heavy shell
EarSonics ONYX (€490)


Driver(s): Hybrid 1 DD (Low) x 2 BA (Mid) x 1 BA (High)
Connector: 0.78mm 2-pin (with 3.5mm default plug)


Impedance: 16.5Ω
Sensitivity: 122dB/mW
Frequency range: 10Hz~20kHz


(1)Matte Black



・Silicone tips
・Foam tips
・Double-flange tips
・Cleaning brush
・Carrying case
・User manual


ONYX was provided by EarSonics as a sample for writing this review. Sound impressions were based on listening with the stock cable and final Type E tips



ONYX came packaged in a rectangular all black (including the text) carton box. It is quite a minimalistic presentation, straightforward and hassle-free. The box can also be opened conveniently by unfolding its magnetic binding

Opening the box, inside you can find the ONYX with cable already attached and rolled neatly inside its case

Next to them, on the right lies the rest of the accessories compartmentialized in another black carton box

In it contains all the tips, and one small cleaning brush



Build quality on the ONYX is quite something and remarkable. Starting from the inside, EarSonics confined each driver using their newly-developed Acrylic Heart Technology, uniting them together securely

It then gets encased in a metallic shell that is matte-black in color, with EarSonics initial 'ES' design embossed on each faceplate

The connector is a standard 0.78mm 2-pin sockets. And the silver-colored cable feels light and easy to wear

Despite its heavier size, the monitor sits comfortably on my ear. Though for longer listening periods, it is less so. There wasn't any DD driver flex to be heard on my unit

Sliced View

EarSonics Proprietary Acrylic Heart Technology


The ONYX has this shallow v-shaped sound signature to it, that is deep and powerful down low, and yet clear well-defined up top. It has good mid-bass emphasis, with the mids slightly warmer more colored

Bass I think is the highlight on the ONYX, as it brings along with it to its presentation this large voluminous bass notes. Its bass doesn't slam too hard, but it makes its presence well-felt with its size and decay, as it has this exceptional mimicry of bass guitars' line vibration

It's quite fast in its attack, and well-kept and controlled as not to bleed overly into the lower-mids, coloring and muddying the sound. The bass also extend and reaches quite deep, however it doesn't rumble too much. It's almost earth-shattering skull-rattling, save for the visceral shaky feel

Bass I hear sounds more on the boosted loose bloomier side, it is sizeable though not that solid nor dense as defined by its note appearance. Its enormity though doesn't seem to ever meddle with its mids, remarkably well-separated and blends nicely together

Soundstage dimension I feel is closer to being deeper than wide. Its depth feels vast as a dive into the deep abyss-like dark sea. Sub-bass is the standout here, as I think it plays a major role in creating this atmosphere with its good sustain post-attack

Mids are a bit recessed in its relative positioning, due to ONYX's sizeable bass. But it remains coherent throughout with no sign of disjoint in the transition or crossing from the bass frequency. Its timbre are on the warmer side, though that said it's not too organic. Neither is it too uncolored nor sterile, somewhat somewhere inbetween retaining a good balance of fidelity, and loads of fun

Treble also remains clear well-tempered, and never becoming too hot or splashy harsh. It's pretty well-defined, imparting enough brightness as to avoid the sound from becoming dull or lacking in any bite. Its treble is quite lively but it's never elevated too far apart from the mids, allowing for a good balanced contrast



  • taken_1644716095725.jpg
    100.5 KB · Views: 0
  • taken_1644715903300.jpg
    85.9 KB · Views: 0
Last edited:
Did you compare it with Early?
You mention price is 490€ but looking at Earsonics webshop they are 590€, did they raise up the price ?
@Xinlisupreme Sorry but I no longer have the Early with me, so couldn't compare 😥
@cocolinho I think that may be the price + VAT, if you're living in EU (link)


Headphoneus Supremus
Earsonics Onyx: analogue beauty
Pros: Sound is analogue: bass deep , big powerful and textured , mids are smooth and weighty without being veiled.. treble smooth and clear . Big soundstage. Build like a tank and high value altogether.
Cons: None


The Onyx concept was born during confinement.
The team of enthusiasts in charge of its development wondered what could be the earphone that would best meet the current demands of the audiophile public.
What started out as a concept turned into a real project.
The ONYX was thus born.


The exclusive team of enthusiasts, the heart of the ONYX project, designed it based on the knowledge and know-how used in the Earsonics laboratories.
After several months of work, the first plans for the ONYX were born and with them the beginnings of an exceptional earphone.
To develop the ONYX, the use of the best materials was the leitmotif of the team.



When developing it, the engineering team used the best.
Thus, the ONYX is based, among other things, on the latest 3D acrylic core technology used for the Grace Platinum, Earsonics flagship.

The specific inclination of the ONYX body and cannula is the result of many years of research guaranteeing a comfortable fit and better insulation.

The use of "2 pins" is still today the safest and most efficient method for connecting your in-ear headphones to their cable.

Entirely handcrafted in our laboratories, the ONYX is designed to offer the highest level of quality at an unbeatable price in this range of high-fidelity headphones.
This result underlines the commitment of the engineers on this project to satisfy the most demanding audiophiles.

ONYX with is 4C-HR cable
1 Cleaning Tool.
2 pairs of comply tips of different sizes.
2 pairs of silicon monoflange tips of different sizes.
2 pairs of silicon bi-flange tips of different sizes.
1 carrying case made from EarSonics.
1 User manual.

I have been interested in earsonics since the beginning , when I started it was expensive for me to even spend $100 or so but slowly I kept increasing my limit years by ears as well as trying different tuning to find my favorite type of sound signature which is definitely analogue and bass forward with mid foward and big soundstage. I wanted to hear the grace platinum and contacted earsonics but they were excited for a secret release of a new iem which I was also interested.so I waited for it. When I got It I was blow away with the package and the presentation. Then I saw the iem which is gorgeous and I pick it up and was like woohoo the weight. It's almost as heavy as the ikko oh10.cable is nice and simple , tips were ok but I changed it out to my favorite spring tips by moondrop.


Bass : the bass is big and bold and hits hard . Even though it's big it doesn't bleed into the midrange and the bass is also very textured and you can feel the air on some of the bass hit.bass speed is above average so it's not slow and laggy and not hyper speed sounding artificial .

Mids :
Perfect harmony the vocals are so good I can cry , they are rendered so realistically you'll feel all the nuance in the breath of the singer being male or female.the instrument also have weight to them and speed to not becoming busy always clear and realistically rendered. Lol .....I was writing the review as I do listening to music but because how fluid and beautiful the audio is rendered I was just enjoying the musix for 15min 😅.

Treble :

The treble is naturally extended and is clear with no artificial peaks or glare but is presented in a real way with weight and tone not like some B's which sounds thin.


For me the fit and angle of the onyx is excellent like I have a custom moulded iem for my ears and with my favorite spring tips it's a winner in every way. The weight of the iem isn't felt because of how secure it is in my ears and I get zero ear fatigue or pain because the shell is smooth and curvy . For sound I 100% agree the a good fit is needed to enjoy these beauty to the maximum.


This is my first time hearing earsonics beautiful tuning and hopefully not my last because I have been truly enjoying every moment of every album with the onyx as the definitely hang with top tier without the top tier price and I hope to see more magic for this awesome company.


  • Screenshot_20220227-185041.png
    1.7 MB · Views: 0
  • Screenshot_20220227-185038.png
    1.8 MB · Views: 0
  • Screenshot_20220227-185033.png
    2.2 MB · Views: 0
  • Screenshot_20220227-185018.png
    2.1 MB · Views: 0
It also depends what sound you are after? Meaning the single ended included silver gets you a more middle of the road balanced sound. The 4.4mm copper cables give you more low end texture and warmth. You can literally play with the presentation after burn-in. Meaning the ONYX actually (while mostly slightly-darker) can fully change to how it represents the music. You can make it slightly brighter up top with a 4.4mm balanced silver cable, or remove that treble engagement to focus on a more L shape tone depending on source and/or cable!

It's by far the best value IEM (and biggest sounding) in its price bracket, if your into the ONYX style of playback. Not even a question about that. That is what it was designed to be; a factory direct value.
  • First of all: I think that the included 3.5mm silver stock cable is already pretty good itself!
  • Imo single ended vs balanced mainly depends on the dap that you're using. I've had daps where balanced made a big difference. On my current daps the differences are very subtle though.
  • I agree with @Redcarmoose that the HanSound Zen (which I also have here) sounds very good with ONYX.
  • The best cable synergy that I've heard so far can be checked over here in the ONYX thread.
Cheers and imho you can believe the hype this time! :)
I have a number of 4.4bal and 2.5bal cables that I would not hesitate to put into the rotation on the ONYX. The Eletech Socrates is a copper/warm cable, so that one might be a bit too much, but I have an Effect Audio Ares II, which while copper as well, would be a good fit for the ONYX.

As @Kerouac stated, the included cable is a very fine cable. Any additional for balanced operation would be the icing on the cake. We all like icing, at least I do. :sunglasses:

Dobrescu George

Reviewer: AudiophileHeaven
Earsonics ONYX IEMs - French Melody
Pros: + Excellent instrument separation
+ Awesome dynamics and a very enagaging sound
+ Great sub-bass and overall clarity
+ Sparkly treble with good overall energy
+ Very good build quality
+ Nice default cable
+ Price / Performance ratio
+ Handmade in France
+ I am very sensitive to driver flex, and they don't have any
+ Most Cons are balanced by the price performance ratio, relative to what you can find on the market at the moment
Cons: - Not enough tips included in the package
- No balanced cables
- Mid bass warmth can be lacking for some songs and music styles
- There are some big discrepancies between impressions of different users, which may indicate that tip rolling, burn-in, cable rolling, or other post purchase processes may be necessary to fully enjoy them, so sound might be tip / cable / source / fit dependent
Earsonics ONYX IEMs - French Melody


ONYX is the name of the latest high-end In Ear Monitor handmade in France by the French company Earsonics, priced at 490 EUROs or roughly 561 USD. This is a proof of art movement made by the company, trying to create the most affordable high-end IEM they could, all while including all their best technology inside an IEM that's made to last. Given the price point, it will be compared to other high-end IEMs like Campfire Mammoth (650 USD), Moondrop Illumination (800 USD), Metalure Wave (600 USD), and NX Ears Baso (550 USD).


Earsonics is getting more and more interesting, but to be honest I'm writing this introduction after having heard the Onyx and having spent some time with it, as it has been under NDA since it arrived to me and until now. I have around 20 IEMS in queue for reviewing at any given moment, so whatever gets ear time for me must be really good, Onyx being an IEM that got absurd amounts of ear time, only in light of its sound. The tech inside is interesting, your top of the line hybrid setup, with BA and Dynamic Drivers, all cast in plastic, then placed inside a metallic case for best sonics. The company is really trusty, answers communications quickly and is deeply involved with music loving communities, being there for you, ready to back their products, which are all hand made in France.


It should be noted that I have absolutely no affiliation with Earsonics, I am not receiving any incentive for this review or to sweeten things out. I'd like to thank Earsonics for providing the sample for this review. Every opinion expressed is mine and I stand by it. The purpose of this review is to help those interested in Earsonics ONYX find their next music companion.


First things first, let's get the packaging out of the way:



The package of Onyx is really nice, but Earsonics is the only company I know that includes only two sizes of tips with their IEMs, rather than three. They have Foam tips, two sizes, double flange tips, two sizes, and single flange tips, two sizes. I like Single Flanged tips the most, both for sonics and comfort.


There is also a high quality carrying case included with Onyx, and the usual paperwork. The cable included with Onyx is a high-end one, and there's also a cleaning tool to keep your Onyx as sparkly as possible. All of this comes in a matte black box, offering a high-end unboxing experience for Onyx.

Build Quality/Aesthetics/Fit/Comfort

The build quality of Onyx is great, they are cast in a metallic shell, with something unique, the Acrylic Heart technology. This basically means that all the drivers inside of Onyx are cast in an Acrylic shell, and they have the True Wave patented technology as well, basically a special tube inside the bore that helps guide the sound in Onyx for the least distortions and reverberations.


We have a combination of dampers and passive filters that help filter the sound of the 4 drivers inside of Onyx. They have a hybrid configuration with a full sized dynamic driver, and three balanced armatures, two for mids and one for treble. The low impedance of 16.5 Ohms means that Onyx is inherently slightly sensitive to hissing, so you should try to use them with a high-end source, my favorite pairings being with iBasso DX240 + AMP 8 MK2, Lotoo PAW 6000, Dethonray DTR1+ Prelude, and Astell & Kern SE180 + SEM2.

The company acquired experience over decades, and while they are extremely popular with music makers and within Europe, some of the USA-based music lovers as well as Asian music lovers may not have heard yet about the company that's actually worth hundreds of thousands of Euros in capital. Onyx is their road to making their best sound affordable and offering it all, along with their handmade magic, for just 490 EUROs.


We have a detachable cable with a 2-Pin connector for Onyx, and the default cable is a high-end UnHr 4C Cable made of Silver. The cable is not very tangle-prone and not springy, and does not carry any microphonic noise. The IEM shell is exactly the same as the one found on Corsa, but that does not mean that the inside parts are the same, just the metallic shell that cancels unwanted vibrations and noise. Metal is theoretically the best material to make your IEMs and Earphones from, but usually tends to suffer a bit from being heavy, and if the IEM is not well designed, you will feel some shocks, like it used to happen with early TRN models. Onyx has no such issues, and having all the drivers isolated in the Acrylic Heart provides the best of both worlds - the sonic abilities of a Metallic Shell, and the customizability and support of the Acrylic Heart.


The IEMs themselves are really comfortable, slightly on the large and heavy side of things, but they fit my ears perfectly. You can remove the faceplate using a screwdriver, but that should not be needed, since the company offers one of the best warranties and support out there. The company is not a consumerism oriented company like most Chifi companies, and they avoid releasing unfinished things often just to push the next, rather refining each product, making them by hand, and offering the best experience possible with them. To achieve this while keeping the cost of Onyx low, they plan on selling those directly only, to cut off distribution costs, so my usual Amazon links may not work until the company hopefully puts the Onyx there.


Onyx has a low impedance, and has an extremely high sensitivity of 122db/mW, but in reality I am around 100 / 150 on Astell & Kern SE180 for a medium listening volume, so they are not exactly easy to get loud despite the very friendly specifications. They are comfortable though, and I never felt like taking them out of my ears, plus from all the testing I tend to be sensitive to poorly fitting IEMs lately, something which will be reflected in most future reviews, Onyx providing an excellent comfort for me. Passive noise isolation is great, with 20-25 dB of passive noise isolation, and the leakage of Onyx is zero, as my girlfriend could not hear me blasting death metal at ear bleeding levels, two meters away from her.

Sound Quality

Earsonics Onyx is the kind of IEM that I tried once and I knew it was love. Some IEMs I appreciate after a while, some I never learn to love truly, and some, like Onyx, I know I love right away. The sound is exactly what I am looking for, in so many ways that you will feel my review is tilted, but the only thing that could tilt my words is the raw performance of what I'm reviewing. If you honestly think I care what any company or third party thinks about my words, you need to remember the reason I am writing - for you - the reader. With that out of the way, I've been using Onyx with a few high quality sources, including iBasso DX220, iBasso DX240, Astell & Kern SE180, Astell & Kern SP2000T, Lotoo PAW 6000, Dethonray DTR1+, and others. Generally speaking, Onyx is somewhat sensitive to hiss, and I recommend high end sources. It also scales a lot with the source, so entry-level sources won't provide an experience that's as fun as flagship DAPs. This being said, iBasso DX160 is more than enough for driving Onyx.


The overall signature of Onyx can be described as engaging, energetic, vivid, U-Shaped and distortion-free. The point to which it is distortion-free is extreme this time around, and this is an IEM with a really strong sub-bass and treble, but which is never fatiguing, an IEM that has excellent imaging and instrument separation, all confined in a natural soundstage. The level of detail that Onyx has is comparable to most flagships like Unique Melody MEST MK2, and Campfire Ara, but all is packaged with an impactful bass and sub bass, the dynamic driver doing an exceptional job at keeping the sound balanced and enjoyable. From the really natural and slightly midrange forward, bright signature that Corsa had, I assumed that the company would always go for pretty natural sound, Onyx only keeps the musicality and beautiful voicing for female voices from Corsa, and packages it all in a much more puchy tuning.

The bass of Onyx is deep, fun, full, impactful and enhanced considerably above the midrange. The sub-bass along with parts of the mid bass are heavily boosted, and Onyx has a strong and bold sub-bass punch, rumble and impact. The bass has a natural to slightly quick character, so it is revealing, and helps recognize textures in electronic music, listening to Rap, EDM, Pop and Dubstep being a really revealing experience, while the whole tuning has enough musicality that Bass in Jazz music, along with Rock is natural and smooth. I am head over heels after having a strong sub bass with my music, especially since I enjoy some hood rap and trap, Onyx being able to deliver bass deep and full enough to satisfy any basshead lusting for some of those lows. The bass of Onyx extends as low as 20 Hz, and is enhanced as high as about 60 Hz, so there's both sub bass, and some punchiness in the mid bass that you feel in your jaw, but you also hear with every drum hit. You could say that they're so rhythmic that they give you a dance fever, you feel the need to stand up, and move your body to the music you're enjoying. Even on very brash songs like Nekrogoblikon - Chop Suey, the chorus has extremely deep and earth-shaking bass notes, presented naturally smooth. The voicing is sweet, and the guitars are always musical and playful, although the cymbals are bright and sparkly. No sign of fatigue, and this is one of those bands everyone finds fatiguing, both in ideology, videographic content, and recording.


We reach the midrange of Onyx, which is something else entirely, really detailed, clean and distortion-free. You don't really understand what distortion-free means here, until you hear another ~600 USD IEM side by side, and feel the need to increase the volume on Onyx because you can. You can hear more of your favorite sounds with absolutely zero distorts, and you can enjoy more of those sweet voices without fearing they will become harsh once you reach ear bleeding levels. Onyx presents music maturely, with a ton of textures, but those are smooth and not fatiguing, plus it has one of the sweetest presentations for female voices, but also natural presentations for male voices. It is immensely musical and enjoyable. Even ethereal sounding music like Mili - world.execute(me); sounds incredibly vivid and sweet, detailed, with a strong bottom end, and a sparkly top end, all without being fatiguing. Switching back and forth with some Chifi IEMs, even those around the price point, you will notice that they are also detailed, but harsh. Somehow, Earsonics managed to apply the passive filters and dampeners in just the right way to make Onyx detailed, yet fatigue-free.

Earsonics managed to deliver a really bright and peppy treble, with tons of air and a healthy extension up to 16-17kHz, yet deliver it in such a manner that it is never fatiguing or too much. The treble texture is fairly smooth, and treble speed is slow, character slightly wet, in such a way that Onyx delivers music enjoyably, yet bright and vivid. It reminds me a lot of the original IE800, and the signature I enjoyed from them, but Onyx is far more refined, more detailed, and has a more musical midrange. In songs like Reol - The Sixth Sense, the treble is presented vividly, sparkly and bright, energetic. The bass is deep, hits with every occasion, while Reol's Voice is as sweet as I've ever heard her.

Onyx has a natural staging, in both width and depth, and their sound is remarkably dynamic and punchy, surprising in how good the instrument separation and overall refinement is. Onyx has great imaging and separation. Bringing the voices and singers slightly closer to the listener is part of why Onyx is so enjoyable, as you hear all that delightful bass, bright treble, but never lose the voicing and forwardness / actual instruments and music from music. We're most sensitive to midrange, and we literally have evolved to listen for human voices, so the way Onyx has a natural stage compliments their sound well, for Rock, Metal, Pop, EDM, Dubstep, Rap and Commercial Music in general, even Punk and Downtempo.



Earsonics ONYX vs Moondrop Illumination (561 USD vs 800 USD) - We have good IEMs here, Illumination is a bit smaller, but not much lighter than Onyx, so the comfort is comparable between them. The sonic presentation is fairly different, with Illumination focusing on having a soundstage as wide as possible, but also losing some treble extension in the process, and some bass extension, Onyx sounding better in both how low the bass can go, but in how high the treble can go, with Onyx having better overall imaging and instrument separation. The resolution and raw detail is comparable between them. Illumination works better with classical, orchestral and music that is supposed to sound wide and expand a lot, where Onyx sounds better with pretty much everything else, especially because Onyx has a special musicality and texture smoothness that makes it more musical, and better controlled at extremely high levels, where Illumination can become a bit harsh. The two do follow a somewhat similar V-Shaped tuning, so they are directly comparable.

Earsonics ONYX vs Metalure Wave (561 USD vs 600 USD) - I still enjoy the Wave every now and then, and it is not an IEM that has faded away for me. The construction quality is equal between them, and a 10/10. The overall comfort is equal, they are about the same weight, and about the same size, and both have a smooth, ergonomic inner part. Wave is deep, lush and full, where Onyx brings more treble and more edginess to the sound. The overall signature is deeper, more lush, fuller, and smoother on Metalure Wave. Wave also sounds more bassy, wider, and has a much smoother texture that flows more naturally, you could say it is more musical. Onyx sounds more edgy, more live, more lively, presents a bit more detail in music, also more dynamics, a more precise stereo imaging, and better overall instrument separation. I love both, but when I feel like a pure basshead I go for Wave, while when I want some treble bite and sparkle, I go for the Onyx.

Earsonics ONYX vs NX Ears Baso (561 USD vs 550 USD) - Nx Ears Baso did not arrive to me with a case, so I am not sure what the default package looks like, but the carrying case is better on Onyx. The default cable is better on Onyx as well. The overall comfort is equal, slightly better on Baso which is somewhat smaller, but also slightly heavier. The sonic presentation is more edgy, more forward, more dynamic and more detailed on the Onyx. Baso sounds smoother, with less treble energy, less bass impact, and a more intimate sound. Onyx sounds wider, with more depth and better overall imaging and separation.

Earsonics ONYX vs Campfire Mammoth (561 USD vs 650 USD) - We have two high quality IEMs here, one that's bass heavy, and one that's V-Shaped. The comfort is equal, although Mammoth is a bit lighter, and smaller. Default cable quality is slightly better on Onyx, which has a thicker, better constructed cable, which is a bit more tangle-prone. The overall design is more edgy, and cooler on Mammoth. The overall sound is much thicker, deeper, more wooly and smoother on Mammoth. Onyx is brighter, more impactful, more dynamic, and presents more detail in music. Mammoth has a slightly wider soundstage, with more depth, but Onyx has better imaging and instrument separation. Onyx sounds more live, more forward, more aggressive, more punchy, Mammoth is smoother and more relaxing.

Value and Conclusion

At the end of the day, Onyx has tremendous value, and consider it is a handmade IEM, offers perfect quality control, plus the company doesn't want to sell you the next IEM next year, they want you to have a long lasting IEM you'll be enjoying for a while. That's something to respect and a good reason to go for a product, Onyx being an excellent example of a well done IEM that could have cost much more for the sonic performance, but the company decided to do every music lover a favor and offer it for a really good price.


The package is not that interesting, and this is literally the only IEM in the whole world that comes with two sizes of tips instead of three, but the construction quality is excellent, cable quality is excellent (silver cable included in the price), and the comfort is superb.


If you're into a strong, vivid, dynamic and punchy sound with a strong sub-bass, strong bass, clean and detailed, distortion-free midrange, and a bright, yet non-fatiguing treble, then Onyx has a superb sound. In fact, where Corsa didn't quite make it to Audiophile-Heaven's Hall Of Fame, Onyx does and this is an IEM I really enjoy on a personal level.


At the end of today's review, if you're looking for a high-end IEM for a fair price, if you want a bold, vivid and dynamic signature with extreme clarity, if you want a handmade IEM, designed by professionals, and if you want to taste what zero-distortion music sounds like, Onyx is an excellent offering and you can taste a flagship for a mid range price with this one, so fully recommended purchase from me.
Cheers! I love this review!
Magnificent review indeed. And around 400 reviews on your own site in just a few years time, hats off to you George! But there's one thing that worried me a bit though: when I read 2x 'listening to ear bleeding levels', I hope you were kidding, right? If not, please be careful my friend. Once tinnitus comes around the corner, it might completely ruin this hobby for you for the rest of your life. All the best...
Dobrescu George
Dobrescu George
@Redcarmoose - Thank you and Happy to help!!
@Kerouac - Thanks a lot friend! I try to minimise the time I spend listening to protect my hearing, but once in a while I do pump the volume up... I guess I miss the old times when I was a teenager and went to rock / metal concerts and had tons of fun, which is what I'm trying to simulate there...


500+ Head-Fier
Long-term Impressions
Pros: Tank-like build
- Nice stock cable
- Bass energy and slam will suit those looking for low-end grunt
- Laid-back, inoffensive mids
- Good coherence for a hybrid
- Good stage depth
Cons: Shells can feel too heavy
- 1.5KHz bump in the mids make baritone vocals sound chesty
- Not versatile for all genres
- Imaging lacks precision, layering could be better
- Middling microdynamics, macrodynamic punch could be better
- Not as resolving as some of their peers


Earsonics reached out to me somewhere around January to ask if I were interested in one of their latest releases. They did not reveal if the product in question were IEMs or something else, and there was also some embargo in place until the launch of the product itself.

Needless to say that my curiosity got the better of me and I only knew about the specs of the IEMs two weeks after receiving them.

The ONYX are Earsonics' latest launch and aims to capture the super-competitive mid-fi market. They are priced in a category I like to term "The Twilight Zone" - the point where diminishing returns start arising. Being a quad-driver hybrid with 3 BA drivers for mids and highs and a dynamic driver for bass, the ONYX got the spec-sheet right for the asking price.

Let's see if Earsonics could create something unique for the price range.

Note: the ratings given will be subjective to the price tier. Thibault from Earsonics was kind enough to send me the ONYX for the purpose of evaluation.

Sources used: Questyle CMA Fifteen, Lotoo PAW 6000
Price, while reviewed: 490 euros. Can be bought from
Earsonics Official store.


The ONYX are absolute tanks when it comes to build. The dense aluminium shells are reassuringly heavy. The 2-pin connectors are recessed into the shells, making the connection more robust than protruded ones.

The shell itself is a two-piece design held together by two small torx-headed screws. The sides of the shell have a unique dual-slit mechanism that apparently relieves the internal pressure.


The nozzle is ergonomically angled but due to the small diameter might not fit every third-party tips out there. I did find the Spinfit CP-100+ to fit nicely, but Spinfit CP-500 slipped out. Note that there is no wax filter on the nozzle, so cleaning them periodically is recommended.


The Earsonics logo is stamped into the faceplate, and this rounds up a rather unique shell-design. I think the Onyx stand out from the rest of the competition in terms of industrial design and are identifiable immediately unlike the regular resin-shell affairs.


Earsonics supplies a nice 4-core cable that is supple and doesn't form kinks easily. The heavy shells do tend to get entangled due to the thinner cable gauge. You also get 6 pairs of eartips (2 pairs of dual-flange, 2 pairs of foams, and 2 pairs of silicone), a hard-shell carrying case, and a cleaning tool. Pretty well-rounded accessory wise.


Comfort and Isolation​

This is where I encounter my first qualm with the ONYX. The shells are too heavy to be listening to the IEMs while lying down, which is something I do often. Also the fit is not the most stable (due to the weight) and can even slip out of the ears without a deep fit.

Isolation was above average with the stock dual-flange tips. The foam tips offer even better isolation so try those out if you need more silence.


The Onyx have a dense, laid-back tuning where the delivery is dominated by low-end.

Sub-bass frequencies are bold and often masks the low-mid details. The mid-bass sits around 7dB below the sub-bass frequencies, resulting in some loss of texture. This gives rise to a unique bass response where the mid-bass sounds muted and lacks impact comapred to the sub-bass rumble.

Such response works well with tracks like Poets of the Fall's Daze but can't keep up in tracks with more nimble bass-line and subtle shifts in mid-bass notes, e.g. American Football's Where Are We Now. This lack of texture is not too noticeable on snares and percussion instruments and the slower decay works well in heavy snare hits.

The midrange is where many will feel divided. I find it a mixed bag, personally. Going by the graph, the unconventional peaking around 1.5KHz should be rather honky and nasal but in practice the sound does not feel so congested.

Most of the times male vocals sound about right, if somewhat laid back or recessed due to the aforementioned sub-bass prominence. This is likely due to the subsequent peaking around 3.5KHz that counterbalances the dip around 3KHz. Baritone vocals, however, sound "chesty" and too dense and lacks articulation at times.

String instruments also lack the bite in the leading edge of attack, with sharply tuned guitars sounding somewhat blunted. Same applies to heavy distortion guitar riffs and other plucked instruments.

The treble follows a similar "peak followed by a dip" nature of the midrange. However, a deep insertion somewhat smoothes out the lower-treble peakiness while a shallow fit exaggerates the bump near 6KHz. This may result in occasional splashiness but again is alleviated by tip-change.

Treble in general sounds muted and laid-back, exemplified by the toned down cymbal and triangle hits on Dave Matthews Band's Crash into Me. This may work for those who prefer a darker treble, but I found it to limit resolution and layering/separation of the ONYX.

Speaking of resolution, resolved detail often seems middling due to the sub-bass' masking effect and rolled-off treble. Imaging is a mixed bag with good left/right delineation but when it comes to ordinal imaging (top-left/bottom-right etc.) the ONYX cannot quite deliver with the same precision. This is often referred to as "three-blob imaging" with things being placed left, right, and center only.

Macrodynamic punch should be excellent here with the bass focus but the slow decay of the driver slightly tapers the experience. Microdynamics were middling too with subtle gradations in volume not being as readily apparent as some of their peers.

One area where the ONYX impressed is staging. Partly due to the tuning choices and partly due to the internal acoustic chamber, the stage depth is very good with vocals being projected somewhat farther away than the center of the head (a issue plaguing most IEMs). Stage width was also good though that may be a byproduct of the lower-mid recession.

Bass: 4/5
Mids: 3.5/5
Treble: 3/5
Imaging/Separation: 3/5
Staging: 4/5
Dynamics/Speed: 3/5

Frequency Response Graph​


The measurements were conducted using an IEC-711 compliant coupler. Questyle CMA Fifteen were used as source (low gain).

Select Comparisons​

vs Dunu Studio SA6​

The Dunu Studio SA6 are my personal benchmark for IEMs around the $500 mark and acts a great reference point while comparing other IEMs in the "Twilight Zone" of pricing.


In terms of build, both are excellent but I will always side with metal if it's metal vs resin so ONYX gets the nod for build quality. Comfort is better on the SA6 though due to much lighter shells. Isolation is about similar on both, whereas the SA6 have better supplied accessories due to the excellent modular cable.

In terms of sound, Dunu put more focus on clarity and resolution than hard-hitting bass. The SA6 is better than most all-BA IEMs when it comes to bass but can't hold a candle to the grunt and physicality of the ONYX's bass response.

Mids are another case though and I personally much prefer the SA6's midrange tuning. I find it to be about perfect for my tastes as not only are vocals articulated, the string instruments sound magnificent with superb tonal accuracy.

The treble is more extended on the SA6 as well with better defined cymbal hits, esp crash cymbals have a more satisfying leading edge on the DUNU IEMs. Staging is better on the ONYX, whereas imaging is slightly better on the SA6 (they are no imaging champ).

Separation and speed goes to the SA6 as the slower dynamic driver on the ONYX feels sluggish in comparison. Dynamics are better on the ONYX, however, with the SA6 having similar microdynamics and slightly worse macrodynamic punch.

Overall, I would pick the SA6 for a more resolving and articulated listen, whereas the ONYX is better suited for bass-driven and energetic tracks.



The Earsonics ONYX have a unique tuning, especially compared to the more popular adherers of the Harman-target (or its variants). The bass response is good and the general coherence is excellent given the multi-driver nature of the IEMs. Earsonics put a lot of R&D into the driver placement and configuration, and that shows.

However, I think the sub-bass is too boosted and the bass driver could be faster. That way the lower-level details would not be as overshadowed by decaying sub-bass notes. I also wish that the treble was a bit more extended since the lack of air impacts the sense of clarity. Imaging could be better yet and the heavy shells are a bit tiring for me.

All that being said, a bassy tuning is not too common in the $500-ish price range and the ONYX offer something for those who prefer a dense, energetic listen. Give this a try if you like your bass to be bold and brash, even at the cost of some fine details.

Edit: re-adjusted rating for 2023.
Last edited:
Thanks for reading the review. I have also read yours (love those Batman gifs) and our experiences are indeed different. I do not use any EQ when evaluating and use reference-class sources. The reason: PEQ is not universal (subtle unit variations may throw off the preset, and every individual hears slightly differently). I tried the "Rock" preset upon your rec and it improved clarity and bass slam, though I found the highs a bit fatiguing.

As for the question regarding burn-in, initially the bass was somewhat "loose" and undefined and it got better with time. I did notice how "burn-in" was being recommended by experienced members and reviewers here for the ONYX, so I decided to cross the 70 hour mark and then write the review.

So the ONYX had about 70 +/- 5 hours of burn-in before writing the review. I will keep using them and I will surely update the review and rating if further burn-in changes things. Cheers!
Thanks for your reply! I'm glad that you didn't see my earlier reaction and questions as some sort of attack (as it surely wasn't meant that way). Your answers just helped me to get a clearer understanding of your review circumstances and approach.

Highly appreciated and happy listening!
I think now is time to wait until Earsonics will make some discount or special offer.
Thank you so much review


Headphoneus Supremus
EarSonics ONYX: The Gotham In-Ear Experience
Pros: Gorgeous, solid build & design
Full bodied and dynamic sound
Great layering & holographic lows
Good soundstage and imaging
Very nice HR C4 silver stock cable
Superb price / performance ratio
Cons: Not for (upper)treble heads
Introduction: Out of the blue and into the black!

At the end of last year I was surprised to receive a pm 'out of the blue' from EarSonics' Thibault. 'Did I ever hear of the company and was I familiar with their products?' Well, that was a two times 'Yes'. Some years ago I had the chance to get the EarSonics Grace and (later on) EM10 on a loan from a friend. Although it's too long ago to remember how those two sounded exactly, I knew that this French company delivered some first class products.

Thibault mentioned that EarSonics was going to launch a new project in 2022, called ONYX. Everything else about it was a secret at that moment, so I got no further information (besides the name) about it beforehand. But if I was interested they would be willing to send me a review sample to shine my light on. And so it all started...

During 2021 I had stopped posting actively on Head-Fi, as I had the feeling that I had not that much to contribute anymore, without repeating myself. I was also done with spending money on new (often highly priced) audio stuff, and I considered my current collection as my personal audio 'End-Game'. Which in my opinion is nothing more/less than just a matter of state of mind, being satisfied with the things that you have at that moment, without longing for more or better.

This however was a chance to try something new, without suffering financially. So, after (very) short consideration, I decided to take on this 'review challenge'. A big 'Thank you!' goes out to EarSonics and Thibault for this 'free review sample' opportunity and this was a great way at the same time to find out for myself what the mysterious ONYX fuss was all about...
GIF 01.gif

About a month after I was contacted for the first time, I received a package from France. Of course I was very curious and wanted (just like Brad Pitt in Se7en) to know:
GIF 02.gif

PIC 01.jpg

Luckily there was a way more pleasant surprise, compared to those two 'movie boxes', inside this one!
PIC 02.jpg

Besides the ONYX and its silver stock cable (later more on that) leading to an EarSonics carrying case, there was also a selection of various silicone & foam tips plus a cleaning tool, inside the smaller accessories box, shown on the right side of the picture above. So basically there was more than enough to get me started on this audio adventure.

Now, the robust heavy build and design of the ONYX, which felt like almost indestructible in my hands, reminded me of this other 'magnificent Dark Metal Beast'
PIC 03.jpg
PIC 04.jpg

OK, before I continue, let's get some things clear: I don't consider myself to be a great technical reviewer (like some of you out there really are), my native language ain't English (sometimes struggling with that) and I only wrote three reviews before this one, so they're almost as rare as a Yeti in the wild. But I like to think that I'm good at creating an atmosphere around an IEM, which can also give you a decent impression of how it should sound.

The association with the 'Tumbler' immediately brought a review theme to mind, and after some days of intensive listening with the ONYX, I decided that it was time to prepare...
GIF 03.gif

...and get to work!
GIF 04.gif

Hey, what? Now it's already time for a short intermission?!?!
Xtra - Intermission.jpg

After I had decided on the Dark Knight theme + review title, and after I already had done a serious ('Why so serious?' some of you might ask) part of my writing, last week this (imo excellent and if you haven't read it yet, you really should!) review suddenly showed up:

This is Batman’s IEM! And......with this soundtrack it’s absolutely perfect. Perfect in every way, shape and form. First off, look at the IEM. Does it look like Batman’s only IEM? Of course it does. This IS the Batman IEM!

GIF 05.gif

What just happened?

Needless to say that imo this reviewer hit the nail perfectly on the head. For at least two weeks I had the ridiculous thought that I had a unique and creative review angle and now even the word 'Experience' , that I chose so carefully in my title, came forward.

Did this guy see Inception (another Nolan movie) and had he found a way to make that concept actually work? I felt excited (loved the review) and frustrated (would I, because of this, have to start all over again from scratch?) at the same time.

Anyhow, all credits go to @Redcarmoose and after a night of restless sleep I decided to just carry on with what I already had. But in this scenario I also felt that the least I could do was to add this 'intermission part', as some kind of explanation.

So, now back to the original program...
Xtra - Logo.jpg

First of all, the ONYX being a universal IEM, I had to check which included tips worked best for me. As I've never been a huge fan of foam tips myself (some people love them) I settled on the included, bigger silicone single- and double-flange tips at first. Later on I also experimented with some other tips, which altered the sound slightly.

Now, as promised earlier, the Cable:
ONYX comes with EarSonics own UnHR C4 (3.5mm, 2-pin) silver cable that also, retails for €99 as an accessoire on their site. It is a very thin and flexible cable without (Hooray for that!) metal ear guidance... It seems to disappear completely once used, so comfort wise it doesn't get any better than this. The choice for silver is also a good one imo, as it has the nature of bringing some more clarity (compared to most copper ones) to the signature.

At some point I decided to swap it for a copper (back-up one, that I still had laying in my closet) Effect Audio Ares II, but after an hour I switched it back, as it was no improvement to my ears. So yeah, I think that the stock C4 silver cable is a good match for the ONYX and I don't feel the need to search for (or try) another upgrade cable myself. To my ears (and I'm a huge cable believer, as some of you know) there's already enough great synergy going on here.

Sources: most of the listening was done from a Lotoo Paw Gold Touch. This is probably one of the most neutral and detail revealing, reference DAPs around. Normally I use some, self created, PMEQ settings for my IEMs. But after some listening I found that the pre-set one called 'Rock' had terrific synergy to my ears with the ONYX. The sound got some more clarity and air around the instruments and treble improved in the overall signature, while the (sub)lows and mids still sounded wonderful this way.
PIC 05.jpg

But listening was also done from a 'RedWine modded' AK380cu, which has a warmer, almost tube like, signature from itself. At first I thought that that might be a miss match (getting too warm overall) with the ONYX, but boy, was I wrong. This also sounded delightful...like a warm summer breeze, but with still plenty of details flying around in the air.
PIC 06.jpg

Btw, on both daps I noticed that ONYX needs a bit more juice (volume) than my other IEMs. For example, using LPGT on high gain: volume for Zeus, Phantom & Andro is usually at (±) 25-26, Solar at 28-30, Prelude & Vega at 30-32 and ONYX at 32-35.

So, what kind of music / files do I listen to?

Normally when I check out new gear, I start with some albums that I know very well, as I've heard them a billion times and then some more (well, in my imagination that is) already. Albums like 'The Dark Side of the Moon', 'Rumours' or 'Mezzanine' in hi-res (DSD 64 / 24 bit FLAC) quality.

There are always some specific sound departments that I pay attention to in certain songs. For instance: the soundstage and details (female voice announcement, left-right footsteps, breathing and helicopter sound effects, etc) in 'On the Run', or how dynamic does 'Dreams' sound at the start, or how emotional and clear does Stevie Nicks sweet, but also nostalgic voice sound, or how does the subbass hold up during 'Angel' by Massive Attack. Enough to get me at least an impression of how this new piece of gear performs.

After that I usually listen to a shipload of different kind of songs (around 1150 artists / 35K songs loaded on a 1TB card, as I'm not that much into streaming, being a dinosaur way kind of listener) in variable (crystal clear souding DSD 64, analogue sounding WAV 32-96, 16 & 24 bit FLAC, but also plenty of 'ordinary', imo also often good sounding MP3 @ 320 kbps files) quality, while using 'all songs, shuffle mode'. So basically almost all kind of genres come along and the playlist stays unpredictable (I like to be surprised) this way.

Now, how does it sound?

Overall I would describe the sound signature of the ONYX as a dynamic, full bodied sound. Slightly dark, but that doesn't mean that it sounds muffled in any way. Nope, it still sounds surprisingly clear to my ears. ONYX especially does extremely well with genres like Rock, EDM or Hip & Trip-Hop. But as a matter of fact I almost liked everything with it so far, and it hasn't disappointed me yet.

Lows: the ONYX produces some of the best (maybe even the best) lows that I've ever heard. There's a clear layering within the lows, without bleeding into each other. Santana's 'Black Magic Woman' just passed by and gave a perfect example of that layering.

At the same time ONYX can rumble and grunt like a thunderstorm, while the intensity of that slowly crawls under your skin.
GIF 06.gif

And while we're on the 'Thunderstorm' subject. There's also one passing by in this song, which came across recently in shuffle mode. It just sounded stellar!

Mids: like I've mentioned before I chose the preset 'Rock' on the LPGT, with the result that guitars started to sound more defined / forward and there was an added clarity overall. Vocals also sounded better / clearer this way. And I can honestly say that I do like the way how ONYX presents vocals, both male and female.

All kind of male voices passed by, in between the range of Jeff Buckley (high vocals) to Leonard Cohen and some other 'musical sort of Dark Knight', Nick Cave (low vocals). When I Iistened to this Copenhagen live performance on my LPGT recently:

...it gave me shiffers to the bone towards the end. The ONYX delivered this in an imo almost perfect way to my ears.

Female voices also passed by in different flavours. From rock legends like Patti Smith and PJ Harvey to more delicate flowers like Laura Marling and Hannah Reid (London Grammar), or 'jazzy ones' like Melody Gardot and Eva Cassidy. It all sounded from at least good, up to superb.

Treble: now this was an interesting part as the ONYX has a signature that leans to the darker side. Because of this the emphasis in the high frequencies lies more on the lower treble. So it doesn't get too splashy or sharp / piercing to the ears, which I consider to be a huge pré (no ear fatigue) during longer listening sessions.

Soundstage: ONYX might not deliver the widest soundstage that I've heard so far, but I would call it above average nonetheless. While a bit more intimate than some (thinking of my Zeus & Andro), this could be even better, as it might come down to a more 'real life experience' this way. Personally I can really enjoy a huge soundstage, but is it also better and more accurate, just because of this preference? I don't know.

Instrument separation and imaging: for this part I like to listen to the start of 'When Poets Dream of Angels' by David Sylvian or to 'Stuck Together Pieces' by Atoms for Peace (in 24-96 FLAC on my DAPs), where the instruments just seem to flow around you in waves during the song.

Imo ONYX does very well in this department. I could clearly hear the variety in distances between the instruments, while delivering a strong image of where they were located at the same time.

And now it's time for some (C)IEM comparisons:

ONYX vs some Custom IEMs
PIC 07.jpg

In the background from left to right: Empire Ears Zeus XR, Warbler Prelude (review 2018), EE Phantom & Rhapsodio Solar (review 2015)

I asked myself: would it be fair to compare the ONYX to my small selection of CIEMs, that I selected and had settled on over the past years, based on the fact that imo most of these were some sort of specialists in their own specific departments?

EE Zeus: high resolution, clarity and wide soundstage
Warbler Prelude: vocals and instrument separation
EE Phantom: natural timbre and superb all-rounder
Rhapsodio Solar: dynamic sound with great lows

All of the above CIEMs costed at least 2-4 times more at time of launch than ONYX, which at that time (some years ago) I guess was considered TOTL. But as I've noticed that IEM prices have been going wild recently (up to around $6K, or even more) I guess these might be probably (not totally sure, as I've been away for a while) considered as mid-fi these days.

I also use some of them with upgrade cables, that already cost more (PW 1960 & EA Horus on Zeus & Phantom) than the ONYX itself. So, I figured that a shoot-out probably would not be fair at all. However, now that I've mentioned this, I thought this shouldn't stop me from trying to compare. So, here we go...

Zeus definitely sounds a lot brighter, with a higher level of resolution. Maybe that level of resolution also has something to do with its brighter sound signature? It has more clarity and I think because of that (micro)details are noticed more easily. Zeus has an impressive wide soundstage and delivers great imaging. But it doesn't come close in the lower frequencies, where the ONYX shines.

Aaaah, the Prelude's lovely forward and highly intense/emotional vocal delivery is hard to beat and it also shines with instrument separation imo. Vocals with Zeus in XR mode come close, but sound less natural and emotional, where the vocals on ONYX are pushed further to the background, but they still sound wonderful that way. This also comes down to personal preferences I guess. Some people like it when there's some more distance between them and the artist singing, where others prefer the illusion of the artist singing right in front of them. ONYX has much better lows and sounds more holographic.

Phantom's best feature is its wonderful, natural timbre imo, but ONYX also sounds quite natural to my ears, although (again) more on the darker side. Soundstage wise I would say that the ONYX is about on par with Phantom and Prelude, not extremely wide like Zeus, but still very good nonetheless. Treble sounds about the same here, with mostly (as mentioned before) emphasis on the lower part.

Now, the one that came closest to the ONYX in sound signature was without a doubt the Rhapsodio Solar. These two obviously shared some signature DNA. Fabulous lows and a full bodied, dynamic sound. But the Solar is build with (10x) balanced armature drivers only, where the ONYX also has a dynamic one inside. Because of that, the Solar can make you hear lows, where the ONYX can make you almost feel them, in a more holographic (3D) way. So this is where ONYX really steals the show from Solar imo.

ONYX vs Andromeda & Vega
PIC 08.jpg

Now, although the two universal IEMs that I already had, Campfire Audio Andromeda & Vega, were launched at around $1K retail, years ago. Somehow it felt more correct to compare the ONYX to these two. Maybe because it's also a universal.

As can be seen in the picture above, the ONYX has the biggest shell of these three. It sticks out more, but comfort wise it is about on par for me with the other two. The ONYX also weights more, but this doesn't bother me at all, once it's in my ears. For me it was very easy (using multiple tips) to get a good fit and therefore seal / isolation, which is especially essential for the lows. Once in my ear I can listen to it for hours, without the need to adjust the fit, so that's a major thumbs up.

Andromeda (I've got the original, early edition) has 5x balanced armature drivers inside and I've always liked its well balanced sound and good imaging over the past years. As I usually don't go outside with my customs, this was often my 'take away' IEM, when I went 'On the Road' (yes, pun intended).

Andro has an impressive wide soundstage, but it doesn't sound as natural (timbre wise) as the ONYX. Imo Andro has a bit of a fun, but slightly artificial flavour to its signature, which doesn't bother me that much personally, but it is there. ONYX also sounds very well balanced although it misses a bit of sparkle in the treble on top imo, the emphasis lies (here we go again) more on the lower treble here. But overall it was an easy pick for me, I prefered the ONYX as it just moved me more on an emotional level, while I was listening

Another Campfire classic is the Vega, which only has 1x dynamic driver inside. I've got the original edition myself and I think that there were some complaints years ago that mentioned 'too spikey highs'. Although I don't think that I have 'bat ears' (or do I?), it never bothered me personally. And if it would have, then I would probably have sold the Vega a long time ago. I also kept it as it has great synergy with my AK380cu.

So, how do the dynamic drivers of these two compare to each other? In both cases it's clear at very first listening that there is such a driver inside. It litteraly moves air and makes the (sub)lows sound clearly better, deeper and more intense than any armature driver ever can.

Dynamic drivers do need a burn-in period to sound at their best though, and I know that this ain't a placebo fairytale, as I've owned (Tralucent 1plus2, Rhapsodio RDB Mk4, Sony XBA-Z5) and heard (RSD Zombie + Galaxy V2 and EE Legend X on a loan for weeks) multipe hybrids in the past.

As I do my burn-in only during listening sessions, I think that I'm somewhere in between the 70 and 100 hours now. However, already, ONYX sounds more holographic (3D) and impressive than the Vega. Better balanced across the frequencies (ONYX has the advantage of extra balanced armature drivers for the mids and highs) and it also produces better layering within the lows.

So, basically if I had to choose between these three universal IEMs at this moment, ONYX would win hands down and I don't think that 'new toy syndrome' plays a major part in this. Also keep in mind that it only costs about half as much as the other two, so that's an impressive quality vs price performance in my book!

Over the past weeks I've also checked (just out of curiosity) the ONYX shortly with other sources, like my smartphone, Bit Opus #1.
And even with my 'entry level' desktop set-up, which I normally only use with headphones.
PIC 09.jpg

To me it all sounded pretty good, but of course: the better the source, the better the final sound quality. This should not be a big surprise to most of you though...

Conclusion and some final words:

When I listened to ONYX at first, I was immediately pleasantly surprised, but when I think about it now, it sounded a bit flat (2D) at first, compared to later on. The dynamic driver needs some burn-in time, so I kept listening and after some time it began to sound more and more holographic, with more and better depth to its sound. The longer I listened, the more alive the sound became. And now I can honestly say that it sounds truly amazing, while it might not even has reached its full potential, as I'm still under 100 hours of listening time.

Now, from what I've understood: ONYX is priced at €590 (VAT included) within the EU. However, for outside EU (and that's most of you out there I guess) it costs €490 (without VAT). It can be ordered directly over here: https://www.earsonics.com/onyx/index-eng.html

In the past EarSonics already had launched two other hybrid IEMs: the Blade (1DD + 2BA) and the Stark (1DD + 4BA). Blade costs €549 and Stark €999 within EU. I haven't heard either of them myself, but the driver count of ONYX is exactly in the middle (1DD + 3BA) of these two. Price wise not though, and as I've understood that's because it can only be ordered straight from EarSonics. So because of this, there are no extra intermediary costs, which results in a lower price than it normally would have ended up with.

Personally I think that at €490/590 the ONYX is a fantastic deal for future buyers, based on its performance and especially in this time where multiple manufacturers seem to go totally wild (imho) with their extreme high IEM prices. Bottom line: to my ears ONYX can easily hold up to most TOTL IEMs that I've heard so far, at a much lower price point.

For me it's also a welcome addition to my own collection, as I didn't have a hybrid anymore for some time. I like to collect different signature flavours (no IEM is tuned perfectly and does everything right imho) and ONYX absolutely brought something new to my rotation table.

Now, with how many stars should I rate the ONYX based on all the above? At first I had plans to settle on 4½ stars, which is already pretty good I guess. And it might have ended up that way, hadn't it start to sound beter and better over time. Besides that, I also just couldn't ignore that fantastic price / performance ratio in this whole story. So in the end, I decided to go for a (drumroll please...) full, 5 star rating.

And what about the Dark Dude himself? I can only imagine that he would approve, as this piece of stylish jewelry and its sound signature should be right up his (Gotham) alley.
GIF 07.gif

For the ones that are interested in even more information / opinions, besides the (already quite a few) reviews that have showed up so far. There's also this dedicated ONYX thread: https://www.head-fi.org/threads/earsonics-onyx.961943/

Finally: it's such a relief, being able to believe that someone is watching over us, as we are wandering through the imaginary streets of Gotham. While listening to our favorite music, during these sometimes confusingly dark (politics / climate / pandemic) times for mankind.

So, what better way to leave, than with those impressive words, so beautifully spoken by the deep voice of Michael Caine (aka Alfred in the DK trilogy) himself, out of another Nolan modern classic:

Do not go gentle into that good night,
Old age should burn and rave at close of day;
Rage, rage against the dying of the light.
And you, my father, there on the sad height,
Curse, bless, me now with your fierce tears, I pray.
Do not go gentle into that good night.

GIF 08.gif

Happy listening to all of ya' out there and stay safe!!!
Last edited:
No, never heard of that "Ark" solo record, have to check it out!
Excellent review. And welcome back, sir. Honored to share a review thread with you.

And yes, the Onyx needs proper burn in to open up fully.

@szore : I thought of tooling down the road in a Grand Tour episode with Clarkson & May in a French car or course. Not for everyone, but quite good nonetheless.😎

Cheers. 👊🏼✌🏼
Even though burn-in is controversial, here it’s mandatory!


Headphoneus Supremus
French gemstone at a reasonable price
Pros: Soundstage, balanced natural tonality, transparency, look, build, no need for serious amplification, suitable for long listening sessions
Cons: None at that price

Many thanks to Thibault from Earsonics for providing a sample for this review.

This is not the first product of Earsonics I have an experience with.
SM64, ES3, S-EM6 V2, ES5 – all these IEMs I owned in the past for a long period of time, especially my favorite S-EM6 V2 which I owned for about 3 years - the first reference tuning IEM of the company that time. So, I can differentiate between Earsonics “house sound” and something new and not typical.


Frankly speaking I did not know what to expect when I was waiting for ONYX. The only thing I knew that it should be an IEM and I did not have a clue about the spec or driver configuration.

I could not imagine what the design of ONYX is and how they look like. The box was not that big as I remember it was with my S-EM6 V2. It is more of the size of ES3 box, I think. Looking at the package size I first thought “is this an entry level IEM?” But when I opened the box, I saw these gorgeously looking monitors in mat black.
They are not tiny and the shell can fit quite a big number of drivers.

When I started first listening session next day after its arrival, I tried to guess what is inside these so good-looking shells…it should have 4 or 5 drivers, at least, I thought. Then I stopped guessing and just started listening.



Besides the IEM with a nice 3.5 mm jack UnHR 4C cable, we have an accessory box with tips (2 x memory foam, 2 x monoflange silicone, 2 x bi-flange silicon), the cleaning tool, manual and the carry case.
This is more or less typical Earsonics package, I think.

The only difference from a previous generation of IEM I owned is a supplied cable. Now it looks more premium and robust. I cannot judge its sonics characteristics vs previous generation stock cables but it does sound good.

For those who are for aftermarket cables, ONYX have standard 0.78 mm pin connectors.
The only thing you should know is the polarity of ES IEM: “plus” is always the nearest pin to your ear canal. I double checked it with a multimeter.


I was close in making some early assumptions about number of drivers and that the bass was sounding more “dynamic” than a typical BA type + these ventilation holes on a rear side made me think so.

The picture below is self-explanatory: 1 x DD - lows, 2 x BA – mids, 1 x BA – highs.


Sensibility: 122 dB/mW
DCR: 16,5 ohms
Frequency response: 10 Hz - 20 kHz

Retail Price: 490 Euro


As I mentioned above, I was pleasantly surprised when I opened the box. Black shells with a silver-colored cable looked like a gemstone on the chain.

The bands on the shell remind me a real onyx.
To my understanding ONYX features a new generation shell design: metal outer shell + acrylic structure inside.
I like this Earsonics’ approach.


The shell of previous generation of in-ear monitors was (acrylic?) a sort of fragile which can be easily damaged if you accidently drop them on the floor. This is what happened with my pair of S-EM6 V2 in the past. ES5 had the same issue and went through a cosmetic repair in France a couple of years ago.

Looking at new ONYX I see it is built like a tank and nothing will happen to it if a real tank drives over them))


Evaluation play list

Avishai Cohen Trio - From Darkness (96 kHz / 24 bit)
Tord Guvstansen Trio - The Other Side (96 kHz / 24 bit)
Alboran Trio - Islands (96 kHz / 24 bit)
BassDrumBone - The Long Road (44.1 kHz / 16 bit)
Jo Kaiat - Come to My World (44.1 kHz / 16 bit)
Sinee Eeg & Thomas Fonnesbak – Staying in Touch (96 kHz / 24 bit)
GoGo Penguin – Man Made Object (44,1 kHz/ 24 bit)
Danish String Quartet – Prism I, II, III (96 kHz / 24 bit)
Kowloon Walled City - Piecework (88,2 kHz / 24 bit)
Ulcerate - Stare into Death and Be Still (44.1 kHz / 24 bit)
Ad Nauseam - Imperative Imperceptible Impulse (44,1 kHz/ 16 bit)
Rome in Monochrome - Away From Light (44.1 kHz / 16 bit)
Carach Angren - Where the Corpses Sink Forever (44,1 kHz/ 16 bit)
Mournful Congregation – The Monad of Creation (44,1 kHz/ 16 bit)
Funeral Moth - Transience (44kHz / 16 bit)
Intaglio – Intaglio (15th Anniversary Remix) (96 kHz / 24 bit)

Reference setup

Roon ROCK > Ifi Audio ZEN Stream > ifi Audio iDSD Diablo > ONYX


The idea behind the setup is to send a signal as clean as possible from the source to a DAC and ensure that the sound is neutral with no coloration.

This red transportable “devil” paired with the streamer can be considered clean and reference source for any evaluation.

Regarding output power it can be an overkill for ONYX so I was running it in Eco mode via 3.5 mm to 6.3 mm adapter. And I must admit that the background noise is nonexistent with Diablo + ONYX combination.

Sound Impressions

Honestly speaking I was never a fan of a hybrid technology in general.

The main issue for me with hybrids was always in the alignment between BA and dynamic drivers and much slower (maybe more natural at the same time) bass attack and decay.

I have to admit that ONYX does not have those typical hybrid problems to my ears. Earsonics engineers did a great job here.

The first thing which you notice is how ONYX builds the soundstage. It goes wide, behind your head from left and right sides and it goes deep at the same time, being on pair with many TOTL IEM.

The next thing you clearly hear is how transparent the sound is. Clarity is the second key feature of the ONYX.
Basically, the clarity cannot be achieved without a proper tonal balance.

The third and the most important thing is a balanced tonality the ONYX IEM has. I don’t hear any big dips or picks. The sound is full-bodied if I may use this term for IEM.

Bass: hits hard with authority and has enough weight and speed to make kick drums and double bass perform great. It goes deeeep. I cannot say if it hits 10 Hz as written in the spec, but it is deep.
Being under Diablo’s control It does not have any issues with crazy fast dissonant double kick drum pedal work of Jamie Saint Merat from Ulcerate, it does not have issues with a double bass passages of Nick Blacka from GoGo Penguin either.

It requires some burn-in time due to its dynamic nature.

Mids: 2 dedicated drivers deliver all information available in the recording accurately and naturally, with a great tonal balance from lower to upper mids.

Highs: detailed and well extended.
It has enough air between instruments to sound freely without any congestion.

Dynamics and overall resolution are also at a very good level.

Ultra-portable setup

Android phone (LDAC) > Fiio BTR5 > ONYX


There are no problems for ONYX to perform well with portable devices like BTR5 considering its sensitivity, it does not require a lot of amplification.
Does ONYX sound good on the go? Yes.

Is there any difference with the performance you get with Diablo? Yes, absolutely.
With BTR5 you cannot achieve this level of control over ONYX bass driver or similar tonal balance since BTR slightly boosts bass, but you still enjoy the pair.


ONYX vs Etymotic EVO

Comparison is tough to make since EVO is my favorite IEM regardless the price and technology applied. Basically, it is the only multidriver IEM I keep in my collection.

Specs. Build. Look.

EVO is 3 BA (2 x bass, 1 x mids + highs)
Both IEM are built like a tank.
ONYX is slightly bigger in size and slightly heavier.

EVO is not easy to drive IEM with the Impedance of 47 ohms and sensitivity of 99 dB SPL at 0.1V. It will not perform great with weak sources or smartphones. It requires some power to shine.
Whilst ONYX is very sensitive (122 dB) and does not require a power station, more versatile in that regard.



Tonality wise EVO is more linear and reference turning with a slight lift of 2-3 dB in sub bass area below 100 Hz.

ONYX has a different nature here due to a dynamic driver. It has more emphases on mid bass which goes all the way to 180-200 Hz. Quantity wise ONYX has slightly more bass presence in general and it can go deeper while EVO is slightly faster.


Soundstage development is comparable in these two, both sound very wide and deep which is not typical for this price category.

Mids are more linear sounding on Etymotic, basically this is in line with all other their products which are typically mid-centric (4S, 4SR). ONYX is more “organic” and “rich” sounding if I can say.

Both sound clean and transparent. The difference here is that ONYX has a DD bass which adds some warmth to the signature.

Treble clarity and level of details are excellent on both, but the turning is slightly different. Due to a more analytical nature of EVO it is easy to pickup all little nuances in that range while ONYX does not throw it in your face trying to keep the balance between musicality and pure analytics.

Both IEM are very dynamic.

As a summary I can say that both IEM are great with their own features and tuning philosophy.

ONYX will be a better choice if you don’t want to bother about a good powerful source and can use your existing portable DAP/dongle or even a smartphone. ONYX will perform anyway from good to great.
ONYX will be also a better choice for those who prefer dynamic bass and foundation it gives to the sound.

Honestly, I would keep both IEM for different occasions or music genres.


I would summarize the sound of ONYX as comfortable and balanced.
It is not too analytical, not being fatigue, and suitable for long listening sessions.

ONYX features an exceptional build quality, and it looks great.

It does not require any serious amplification and can be used with a regular smartphone if needed.

I don’t see any serious cons taking the price into consideration.

Onyx is like a good French cognac which looks nice and tastes great!

Last edited:
wow! 8 Onyx reviews posted on head-fi in 5 days, back to back :) talk about pressure :p
thanks for the great review 😊 do you use the standard Bax T2 cable with the Evo? did you try the T2 Superbax? i would like to know is it worth getting the T2 Superbax balanced 😎 thx
I used the standard T2 cable (so both IEMs were used with a SE cable) in this comparison but I have a custom balanced cable (not Superbax) with T2 connectors I bought from Linum in Denmark (modified Forza Hybrid IEM cable). I made it to utilize Diablo's full balanced circuity (4.4 mm output). I have never made any serious comparison between those two cables, all outputs on Diablo sound great). Maybe separation and soundstage is slightly better with the 4.4 mm cable.

By the way, I sent today a Plussound Poetry 4.4 mm cable for modification to use it later with ONYX.


100+ Head-Fier
EarSonics ONYX: masculinity and a hot heart
Pros: Sound, design, workmanship, price.
Cons: No (but would have liked more tips included).
Bonjour mes amis!

How long have I wanted to speak French for a long time and now I found an excuse. I am pleased to report that I have received a terrific guest from France, who, like a true Gascon, is hot, cool in temper and impeccable in manners.
Yes, it finally happened: the EarSonics brand, which I respect, presented a new IEM ONYX model!

Moreover, ONYX is a unique product even for such masters as EarSonics. The company set itself an extremely ambitious goal - to create a very high-end IEM at an unprecedented price, and brilliantly coped with this task!

Moreover, a special website has been created for ONYX direct sales without any intermediaries, and since February 8, these IEMs are already available for ordering there.
ONYX has a similar design to the Blade and Stark models we reviewed earlier, a hybrid design but with four emitters: (1DD / 3BA). And the sound setting, as it should be, is different from its predecessors.

Let me take a short excursion into the glorious history of EarSonics, in case one of our readers is not familiar with it. ES engineers were at the origins of the creation of IEM based on BA drivers. It was they, along with brands such as Westone, Shure and UE, who were the first to manufacture inear monitors and CIEMs based on 2, 3, 4 or more armature drivers / receivers.
My acquaintance with the products of this brand began quite a long time ago, about twelve years ago, when I had the opportunity to listen to their models SM2 and SM3. A little later, I used SM64, SM2-IFI, EarSonics Velvet, S-EM6 V2, then Blade and Stark.

As in the case of earlier IEM models, the company's engineers approached the development of ONYX with all responsibility, and the sound of the new earphones turned out, in my opinion and hearing, truly amazing. Therefore, we uncork a bottle of Burgundy and begin our acquaintance with our perky Frenchman.


Text: Alexey Kashirskey (aka Hans Barbarossa)

Sensibility: 122 dB/mW
Frequency response: 10 Hz-20 kHz
DCR: 16, 5 ohms
Drivers (4): 1 DD dynamic, 3 BA drivers with 3-way HQ impedance corrector crossover

Appearance, kit and ergonomics

The black cardboard briquette in which the headphones are placed is minimalistic. On its front side, the name of the ONYX model is large, and the EarSonics logo modestly perched there in the lower right corner. That's all, no pompous self-presentations, because we are here to hear something special, and not look at pictures.



We open the box and take out all the contents from it: our IEMs with a detachable silver-white cable already attached to them, four pairs of silicone tips (2 double-flange and 2 standard single-flange), two pairs of Comply foam tips of different sizes, a solid hard case with a zipper, a brush for cleaning the sound pipes and a warranty card with instructions. The kit is extensive, but, as practice has shown, the assortment of tips could be increased.



It is believed that onyx is a mineral with strong masculine energy and healing properties, and among the ancient Greeks, Aztecs and India it was a stone that helped the leaders boldly go towards their goals. Whether this is true or fiction - I don’t presume to judge, but the above qualities can definitely be attributed to the hero of today's review. He has both an impressive "masculine" appearance and an expressive "male" voice.

The case of ONYX, like that of its brothers Stark and Blade, is completely made of metal. As far as I know, the designers used anodized zinc and magnesium. The textured black and matte IEM shell on top, with a faceplate, looks like the contours of intergalactic alien ships from old sci-fi films. And the inner side of the case with three textured transverse lines, emphasizing the curve of the shell, resembles the banded structure characteristic of onyx.

In general, the construction of ONYX, Stark and Blade is similar, the difference is only in color and, possibly, in the alloy used. For my taste, ONYX looks more strict and impressive due to the black coating, but otherwise everything is similar.



On the outer front panel, in the very center, among the graceful stepped forms, there is a convex logo of the "ES" brand. There is a sound pipe on the front, which smoothly passes to the inner part of the case, the shape of which resembles a custom shell with textured transverse lines.

On top is a 2pin connector for connecting a cable. On the back of the earphones we find two oblong compensation slots designed for the correct acoustic design of the dynamic radiator, and just below you can see a screw fastening the two halves of this intricate art object.



Inside the metal structure is a 3D acrylic core, specially designed for the IEM ES hybrid line, with four drivers: 1 dynamic driver handles Lows, two BAs are responsible for Mids, and another 1BA reproduces high frequencies.

A separate chamber is allocated for each set of drivers, which allowed engineers to carefully adjust the sound of each of the emitters. And the new impedance crossover-corrector created by EarSonics, combined with EVS and FUSION technologies, allows IEM to sound without any phase distortion, clearly, accurately and at the same time extremely musical.

The tactile sensations when touching the ONYX are amazing. These earphones are truly a work of art! It can be seen that the developers did not save on materials and, more importantly, in addition to the concentrate of engineering thought embodied in complex schemes and precise details, they put their soul into their brainchild.

The assembly, in my opinion, is flawless, which is not surprising, because the headphones are handmade in France!




Despite the tangible weight that is felt when you hold the IEM in the palm of your hand, ONYX sits easily and comfortably in your ears. Seriously, during a long walk, for some time I even forgot that two black musical weights were traveling around the city with me.

Wearing an IEM, as you probably already understood, is supposed to be behind the ear.


The four-core "HI-RES 4C Silver" cable is braided, it is extremely light, soft and elastic. Connector TRS 3.5mm L-shaped with gold, 2pin connectors that allow you to easily pick up another wire with the same connectors to these IEMs, if necessary. The cable is good in every way, so I see no reason to change it to another one. The only reason, in my opinion, is the transition from a 3.5 mm connector to the now popular balanced connection of 2.5 or 4.4 mm.



This is where I propose to finish our acquaintance with the exterior and technical side of our ONYX and insert them into the ears, which, believe me, have already been waiting for this moment.

Sound impressions

Before using ONYX were burn-in for 70-80 hours.

Listening was conducted with: MyST (NOS) DAC/AMP 1866OCU V.2, Lotoo paw Gold, iBasso DX240, DX300 и DX220 MAX, QLS QA-361, iFi xDSD Gryphon, HIP-DAC2, Go Blu & iFi iDSD Diablo.

With all the listed audio devices, EarSonics ONYX played flawlessly.


As always, and this time especially strongly, I recommend taking the time to both burn-in and select tips, since both of these simple procedures significantly affect the final sound picture.

I can't help but share my experience of finding the right tips for these IEMs. For example, using medium double-flange silicone tips, I got an unusually rich, expressive sound, with amazing reproduction of timbres and reverbs in the lower register, excellent dynamics and slight accentuation of the high-frequency range. Sometimes, when listening to rhythmic compositions, an illusion is created that the headphone case vibrates from beats to the beat, synchronously with the movement of the diffuser, dynamic driver. And this, I want to tell you, is impressive. But at the same time, the sound pipe is not deep in the ear canal, and the earphone body protrudes a little from my auricle. Although my ears are quite "capacious".

Then, after a lot of experimentation, I found three-flange silicone tips in a drawer with a slightly elongated stem and an outlet that matches the diameter of the ONYX sound pipe, and I managed to achieve a deep fit in the ear, flush.
As a result, I got a slightly more balanced sound, losing some of the texture of the lower register, but gaining an overall smoother frequency response and more restrained high frequencies. A similar result is shown by the complete Comply foam tips.

Well, speaking even more broadly, then, of course, the impact on the final sound result when choosing tips will also depend on the individual structural features of your ear. In any case, this is only a "tuning", in which the main character of the ONYX sound remains unchanged. And the sound is in any case, without exaggeration, excellent.



The sound of the Earsonics ONYX is well balanced, massive, dynamic, extraordinarily rich and very melodic, with a neatly dominant low-frequency range, well-textured, tight and nimble bass, amazingly detailed scenic Mids and a clean, slightly sparkling high-frequency range. This is an unusually beautiful and harmonious manner. I understand that for many my maxim will now sound unexpected, but ONYX seemed to open an audio portal to me in the golden age of Hi-Fi, recalling the sound of the legendary Otto SX-P1 speakers.

The frequency response of Earsonics ONYX sounds like a smooth W-shaped wave, where one register harmoniously flows into another. The result is boundless drive, bubbling emotions and uniform interweaving of one frequency range with another. These IEMs show a wide dynamic range and amazing volume reproduction, with a wide stereo panorama and precise localization of apparent sound sources in space, where every musical instrument and every note played is exactly in its place.



The ONYX's sound is grown-up, rich in timbres, comfortable, with a darkened background and charming melody. Such a contrasting, picturesque and energetic manner has a disarming effect on the listener, who, from the very first bars of his favorite compositions, is thrown into a seething musical stream. You dive into this bottomless pool without hesitation, because real audio treasures are waiting for you there.

These earphones build a wide sound stage with amazing depth of virtual space. It's a massive soundscape, rendered in a smooth, velvety manner with black backgrounds, embossed, 3D audio imaging, and amazing detail. The ideal consistency of the drivers and the complete absence of phase distortion are striking. Here reigns the law of harmony of sound.



The lower register is worked out accurately, with a dense, massive and rolling impact, elastic, timbre-rich, textured and agile bass, which boasts excellent articulation and good speed characteristics.

The embossed bass parts sound thick and rich, very dynamic, they roll over the whole body, bitingly and crushingly outlining the rhythmic basis of the composition, filling the middle with depth and lively, weighty substance. The peals of the beats of the drum set scatter like booming artillery shots, accurately conveying the force of the blow. At the same time, it should be taken into account that the low-frequency range is moderately forced and its processing takes quality rather than quantity. The dynamic driver here is configured very sensibly!

Mids is clean, velvety, with a slight smooth and "delicious" color in the mid/high junction area, which makes the vocal parts sound especially expressive. Musical images are drawn magnificently, beautifully and gracefully. String instruments sound fine and beautiful, the resonance of strings with a guitar deck, wind instruments and openwork piano tunes - everything is transmitted lively and harmoniously. Earphones contrast and harmoniously lay out the palette of sounds, accurately and proportionately working with macrodynamics and macrocontrast.
Power, emotions, drive and academic manners are perfectly combined here. Each timbre, voice vibration or string trembling is transmitted extremely naturally, richly and deeply.
Listening pleasure is extraordinary. This is a noble, well-balanced and at the same time emotional performance, where all the elements of the composition are presented in an unusually smooth, informative, precise and multifaceted manner.

High frequencies sound clear and legible, refined, with good articulation and enviable correctness. Here there is a slight accent in the form of a light unobtrusive spark, but in general the register is transmitted quite clearly and distinctly, without excessive sharpness and distortion.
In this case, Highs add contrast, expression and fresh air to the overall sound.
I think that many people will like this approach to sound processing.



Needless to say, with such outstanding skills, Earsonics ONYX can easily cope with jazz, instrumental and classical music, electronics, rock, new wave, and various brutal genres.


Usually I talk about the price of a product at the very, very end, but today I will allow myself to break the usual pattern. The fact is that during the testing of ONYX, I still did not know what price tag the company would put on them, and based on the results of the auditions, I expected that the cost would gravitate towards the bar of 1000 €. However, ONYX can be purchased from the earsonics.com online store for 490 €, and this, my friends, is just a gift for true audiophiles! Considering all the outstanding features of the IEM model, I can definitely say that this is a win-win deal for those who want to hear their favorite music in amazing sound.

ONYX is an amazing IEM model with a truly European flavor, dynamic, well-balanced, harmonious and extraordinarily beautiful sound. Separately, it should be noted the highest performance (manual assembly in France) and impeccable design. Without a doubt, the new product from Earsonics will be revered and loved by audiophiles and music lovers.

Last edited:
I'm starting to think you like these, thanks for an excellent review. I'm looking to get the DX240 so these should meld together quite nicely.
Cecala Thanks so much. Yes, in my opinion, DX240 + ONYX is a good pair.
When no cons man is doing a review something is not right.
You can not have a review so bad by RikudouGoku and this product has no cons.
Someone here seems to be called when you need to sell a product...


Member of the Trade: RikuBuds
Pros: Stage depth
Metal shell
Made in France
Cons: Overpriced is an understatement
Everything sound
Pressure build up AND driver flex
Heavy shell

Disclaimer: I received this review unit for free from Earsonics, thank you very much.

Price: 490 euro


Sensitivity: 122dB/mW

Frequency response: 10Hz-20kHz

DCR: 16.5 ohms



M/L Silicone tips

M/L double flange silicone tips

M/L Foam tips

Cleaning brush

Carry case


Cable: 4-core cable, metal divider/connectors and has a working chin-slider. The 2pin connector is extremely tight though and is very hard to detach.




Build: Full metal build and is very heavy. The nozzle doesn’t have any filters in it so getting dirt/wax in it could be a cause of concern and the nozzle itself is very thin so not a lot of tips fit it. Shell is pretty

Fit: Fit itself is good although it is pretty big, there is a strange effect where at insertion it takes 2-3 seconds before the pressure dissipates (during which time the sound is very weird), similar to what happened with the Tri i3 Pro.

Comfort: Not that good for me due to the big shell which is borderline too big for me, there is some pressure build up and slight driver flex and the shell is very heavy.

Isolation: Above average, big shell helps it.

Setup: Schiit Asgard 3 (low-gain, volume around 8 o´clock), stock tips (single flange) L, stock cable 3.5mm

A ton of mid and sub-bass, focused on sub-bass but since there is a lot of mid-bass as well, it isn’t that clean and is on the looser side, speed is pretty average but it does end up sounding bloated.

Mid-bass: Metallica – fight fire with fire (01:11-01:52), decently clean, fast and tight despite the big quantity, texture could be better. The (02:55-03:01) section with the chopper is hearable, although not very clean.

Hiroyuki Sawano – Pretenders (01:18-01:47), a lot of quantity, is decently fast/tight and with good texture.

Sub-bass: Djuro – Drop that bass (01:15-01:30), extends pretty low and rumbles a lot, although not very clean. Punch quantity is high but is loose, decent speed and texture.

Will Sparks – Sick like that (03:08-03:22), a lot of quantity, decent texture but could be faster and tighter.

Mids: Both male and female vocals are very recessed, quality wise they struggle because the bass is bleeding into the mids and making it very unclean. Not for mid lovers.

Female-vocals: Hiroyuki Sawano – OldToday (01:25-01:52), vocal tonality is too warm, lacking clarity and timbre is a bit off, very recessed as well. Instrument tonality is decent but there is bleed from the mid-bass and it is unclear, timbre is a bit off.

Yuki Hayashi – MightU (01:58-02:55), vocal and instrument tonality are way too warm, lacking a lot of brightness and clarity, vocals are very recessed as well.

Evanescence – Bring me to life (01:18-01:35), vocals aren’t shouty nor peaky treble.

Hiroyuki Sawano – Crescent (02:07-02:26), vocals aren’t shouty but treble is a bit peaky.

Male-vocals: Hiroyuki Sawano – Pretenders (00:57-01:17), vocal tonality and timbre are decent, does lack some clarity and is recessed though.

Hiroyuki Sawano – Scapegoat (00:57-01:17), vocal and instrument tonality is pretty good but lacking clarity, has bass bleed and recessed timbre, decent timbre.

Treble: Linkin Park – Shadow of the Day (03:24-03:42), electric guitar isn’t sharp but they do lack some texture and timbre could be better.

Deuce – America (03:03-03:16), not fatiguing treble but imaging and separation can’t keep up, chaotic.

Hiroyuki Sawano – Lose (string version) (01:22-01:59), cello tonality, timbre and texture are pretty good but lacking clarity and sounds bloated.

Hiroyuki Sawano &Z (02:18-02:57), tonality could be better, lacking clarity and sounds bloated, timbre is decent.

Soundstage: width is average, but depth is pretty impressive and is holographic.

Tonality: Warm V-shaped, note-weight is a bit on the thicker side, does suit my library pretty well but the very recessed mids makes it a poor match for vocal focused genres.

Details: Macro-detail is decent, but lacking in micro-details.

Instrument Separation: Separation and imaging are heavily bottlenecked by the massive bass.

Songs that highlight the IEM: https://www.youtube.com/watch?v=vMRxHpcKjEY https://www.youtube.com/watch?v=bKDdT_nyP54 https://www.youtube.com/watch?v=2IH8tNQAzSs

Good genres:
Hip-Hop, R&B, EDM

Bad genres: Acoustic/vocal tracks, OST, rock/metal


Blon BL-03 (mesh-mod), Radius Deep Mount tips L, cable B3 4.4mm
graph - 2022-02-12T165212.226.png

Bass: Djuro – Drop that bass (01:15-01:30), extends deeper and rumbles more on the Onyx. Punch quantity is higher on the Onyx, similar texture, but a bit faster/tighter and cleaner on the 03. More tonally correct and better timbre on the 03.

Hiroyuki Sawano – Pretenders (01:18-01:47), more mid-bass on the Onyx, similar texture but tighter/faster and cleaner on the 03. More tonally correct and better timbre on the 03.

Metallica – fight fire with fire (01:11-01:52), a bit cleaner on the 03 due to the cleaner (tighter, faster and less bass quantity) bass.

Mids: Hiroyuki Sawano – OldToday (01:25-01:52), vocals are more forward, cleaner, much more tonally accurate and with much better timbre, similar detail. Instrument tonality is better on the 03 and with much better timbre, cleaner on the 03 but similar detail (heavily bottlenecked technicalities on the Onyx).

Evanescence – Bring me to life (01:18-01:35), vocals are a bit shoutier on the 03 but treble is a bit peakier on the Onyx.

Hiroyuki Sawano – Scapegoat (00:57-01:17), vocal and instrument tonality and timbre are much better on the 03, cleaner on the 03, similar detail.

Treble: Linkin Park – Shadow of the Day (03:24-03:42), electric guitars are a bit sharper on the Onyx, more tonally correct and much better timbre own the 03.

Hiroyuki Sawano – Lose (string version) (01:22-01:59), Cello tonality, texture, timbre and clarity are better on the 03, similar detail. Violin tonality, timbre and clarity are better on the 03 similar macro-detail but better micro-detail and treble-extension on the Onyx.

Hiroyuki Sawano &Z (02:18-02:57), tonality and timbre are better on the 03 and cleaner.

Technicalities: Shiro Sagisu – Hundred years war (02:24-02:57), wider and much deeper soundstage on the Onyx. Imaging, separation and detail are comparable due to the massive bottleneck the Onyx has due to its bass. Timbre is much better on the 03.

Overall: The Onyx has an excessive and way too much bass even compared to the 03. The 03 is tuned a lot better and timbre is also a lot better on it, comparable technicalities due to the bass bottleneck on the Onyx.

OnyxBL-03 (mesh-mod)

Dunu Falcon Pro (reference filter), Elecom EHP-CAP20 tips L, stock cable 4.4mm
graph - 2022-02-12T165840.912.png

Bass: Djuro – Drop that bass (01:15-01:30), extends lower and rumbles more on the Onyx. More punch quantity on the Onyx but less textured, slower and looser than the FP. A bit more tonally correct on the FP and with better timbre.

Hiroyuki Sawano – Pretenders (01:18-01:47), more quantity on the Onyx, but more textured and cleaner (faster/tighter) on the FP. More tonally correct and with better timbre on the FP.

Metallica – fight fire with fire (01:11-01:52), lower bass quantity on the FP, a bit faster/tighter, similar texture.

Mids: Hiroyuki Sawano – OldToday (01:25-01:52), a lot better tonality and timbre on the FP, pretty unnatural on the Onyx and more recessed on it. Instrument tonality is a bit better on the Onyx but better timbre, detail and clarity on the FP.

Evanescence – Bring me to life (01:18-01:35), slightly shoutier on the Onyx and peakier treble.

Hiroyuki Sawano – Scapegoat (00:57-01:17), vocal and instrument tonality and timbre are a lot better on the FP, cleaner and more detailed as well.

Treble: Linkin Park – Shadow of the Day (03:24-03:42), electric guitars are a bit sharper and has worse timbre on the Onyx.

Hiroyuki Sawano – Lose (string version) (01:22-01:59), Cello tonality, timbre, detail and clarity are better on the FP, similar texture. Violin tonality is a bit better on the FP, a lot better timbre, detail and clarity on the FP, slightly better treble-extension on the Onyx though.

Hiroyuki Sawano &Z (02:18-02:57), better tonality and timbre on the FP, cleaner and more detailed as well.

Technicalities: Shiro Sagisu – Hundred years war (02:24-02:57), stage is a lot wider and deeper, more holographic on the Onyx. Better separation, imaging and detail on the FP. A lot better timbre (and coherency) on the FP.

Overall: The Onyx has even more mid-bass than the N3 and a lot more sub-bass, more recessed mids and peakier treble. FP has a lot better tonality, timbre and also an edge in technicalities.

OnyxFalcon Pro (reference filter)

Sony XBA-N3, Final Audio Type E tips LL, cable A6 4.4mm
graph - 2022-02-12T165930.084.png

Bass: Djuro – Drop that bass (01:15-01:30), similar extension but rumbles more on the Onyx. More quantity on the Onyx, but more textured and a bit faster/tighter on the N3. More tonally correct on the N3 and with better timbre and coherency.

Hiroyuki Sawano – Pretenders (01:18-01:47), more quantity on the Onyx but more textured and cleaner due to the faster/tighter bass on the N3. More tonally correct and better timbre on the N3.

Metallica – fight fire with fire (01:11-01:52), more quantity, but more textured, faster and tighter on the N3 and cleaner.

Mids: Hiroyuki Sawano – OldToday (01:25-01:52), vocal tonality is more accurate, forward, cleaner, more detailed and better timbre on the N3. Instrument tonality and timbre are better on the N3, cleaner, more detailed on it.

Evanescence – Bring me to life (01:18-01:35), slightly shoutier vocals on the Onyx and peakier treble.

Hiroyuki Sawano – Scapegoat (00:57-01:17), vocals are more recessed on the Onyx. Vocal and instrument tonality, timbre, detail and clarity are better on the N3.

Treble: Linkin Park – Shadow of the Day (03:24-03:42), electric guitars are sharper and more fatiguing on the Onyx, better timbre on the N3 and a bit better tonality.

Hiroyuki Sawano – Lose (string version) (01:22-01:59), Cello tonality and texture are similar, but better timbre and detail on the N3. Violin tonality, timbre, detail, treble-extension and clarity are better on the N3.

Hiroyuki Sawano &Z (02:18-02:57), better tonality, timbre, cleaner and more detailed on the N3.

Technicalities: Shiro Sagisu – Hundred years war (02:24-02:57), Wider on the Onyx but deeper and more holographic on the N3. Better imaging, separation, detail, timbre and coherency on the N3.

Overall: The N3 stomps the Onyx hard, tonality, timbre and technicalities are all better on the N3.


Absolutely ridiculous pricing, even excluding the sound (which is competing in the sub 50 usd range) there are major design errors here (pressure build-up, driver flex, no filter in the nozzle, heavy shell). Go back to the drawing board and try again…

graph - 2022-02-12T164817.452.png

Cable source:


Reference/test songs:

Even though burn-in is controversial, here it’s mandatory!
  • Like
Reactions: 554130
BURN IT IN 150+ hours!
love this review, good work as always! 🔥


Headphoneus Supremus
The 'flanker' you never saw coming.
Pros: Price to performance
Build quality
Bass performance
Clear vocals
Resolving treble
Cons: Fitment may not work for some, as is with all universals
Cable feels cheap but I believe that's to reduce cost
No flared end for tip retention
EarSonics ONYX

A big thanks to Thibault from EarSonics for entrusting me in the review and deployment process for this exciting new product. They even used a picture I provided them early on for their technical sheet which was a pleasant surprise!

If you want them, which you should, they can be ordered factory direct here!



Metal black mat shell
Sensitivity : 122dB/mW
Frequency response : 10Hz-20kHz
DCR: 16.5 ohms
Drivers (QUAD)
1X dynamic bass
2X balanced medium
1X balanced treble


So, as many others, I was sent this unit in exchange for my honest review. I had no idea of the configuration, and I got the good old diversionary tactics when I probed for information. I took that as a blessing to let my ears do the judging, devoid of any expectations based on price or internal components. Keeping that in mind, I was fortunate enough to have been provided with the tech specs prior to releasing this review. This allowed me to revisit my initial findings, now comparable with my newfound knowledge of price to performance. This brings me to my point, which I felt was compelling, as I thought the ONYX was performing in the $1200-$1500 range. I also thought there had to be much more going on inside to produce what I was hearing. This was humbling and quite a deviation from the on-going trend of cramming components inside and demanding asinine prices. This level of performance resting in between the $500-$600 range is quite an accomplishment. One I would have never guessed. Hats off to EarSonics.


After a fair bit of throwing any genre at them where adequate amounts of bass need to be rendered to achieve the intended sound, I was pleasantly surprised. The ONYX pumps out extremely fast, clean, and deep bass. Keeping that in mind, it never overwhelms the other frequencies and isn’t overly elevated. The decay is reminiscent of BA texture and speed, but it is dynamic driver bass. They have managed to deploy some of the fastest and tightest DD bass on the market today, with the exception of titans such as the Empire Ears Legend EVO. The deeper sub bass registers grunt out the 30hz region before rolling off and being unbale to project those wildly almost indiscernible 10-20hz notes. The sub bass rolls linearly into the mid bass, which puts off a nice snappy punch that is palpable. Upper bass is nicely present while responsive and fills out the sound profile without giving off that zingy almost ‘boing’ type noise when drivers distort from the higher pitched bass frequencies in a busy, layered passage.


So, I figure that I will just get this out of the way now... the ONYX probably has the most pronounced and crystal-clear vocals I have heard in an IEM. They are dead neutral with good body and live above all else in the frequency response range. It’s like they are on their own channel. Not sure how they did it. The non-vocal response of the ONYX mid-range is clean and very resolving. Instruments have a crisp snap to them in addition to bearing enough weight to not sound dry and clinical. Going from the lower to upper mid-range, there is no harshness or accentuation to the upper mids. At first, I was expecting some decently elevated upper mid action based on how damn resolving and present the vocals were, but that was not the case. The upper mids are well reserved and never gave me a feeling that they were too much. They also separate nicely from the vocals that fall in the same response range, which is a nice party trick.


The top end is akin to the mid ranges presentation as it is very perceivable but never gets to the point of over-doing it. There is a balanced sparkle with sufficient air and no thinness or sharpness from heavy cymbal crashes. The word elegant best summarizes the treble rendering of the ONYX. Tonality wise, the treble retains a bit of warmth, which gives it a nice body to co-exist with the powerful nature of the ONYX. It is not overly warm but it’s warm enough to have personality and avoid analytical, or sterile precision. These aren’t for mixing and mastering, after all. In the interest of not being overly wordy or carrying on, the treble is great. It does nothing wrong and blends well with the entire signature flawlessly.


Layering and separation are the first things that stood out to me upon first listen. There is not bleed over in any of the frequency range transitions. They remain well divided without losing coherence. Staging is a bit above average due to this perceived level of sounds living in their own space while coming together as one. It’s not a spherical out of head experience like the $6500 Oriolus Traillii or the $3000 Empire Ears Legend Evo but it’s more than acceptable in the HiFi realm. Tonality is what I would consider as a warm-neutral due to the crisp detail that cuts through the powerful sub bass and punch. Tuning sounds to be a fairly linear ‘W’ shaped sound signature.



As mentioned previously, these comparisons were set into motion based on what I heard, not knowing price range or it’s technical prowess. I’ll keep this part very simple….

ONYX vs. Andromeda 2020: The Andromeda comes out a bit warmer and more analogue in nature, but I personally preferred the overall coherence and bass performance of the ONYX, which is where the Andromeda falls behind.

ONYX vs. MEST MKII: The ONYX really makes a compelling argument against the MEST. It’s performing nearly the same, provides much of the wow factor delivered by the MEST but is a heck of a lot less to get there. Aside from the obvious advantages that the MEST receives from its bone conduction, the ONYX goes toe to toe with it. Bass is nearly the same but a bit punchier with ONYX, Mids are both revealing and tonally similar. MEST treble is a just a bit more extended but also thinner sounding. Staging is the most obvious difference between the two, as MEST provides that oval out of head experience and the ONYX is of typical staging without bone conduction.

ONYX vs. Legend X: I had to compare ONYX against, probably my all-time favorite, Legend X. This was by no means fair, but it did provide an interesting data point, as to where I felt the ONYX lived amongst the giants, knowing nothing about it besides how It performed. Bass wise, there no competition, the Legend X kills most everything in this department still to this day. The ONYX however does not feel as if it lacks bass or dynamics in this region, even after comparing it to the Legend X, which is an accomplishment in and of itself. The mid-range, especially vocals of the ONYX are a good deal more revealing and clearer, but the Legend X has a buttery smooth mid-range that just feels right; natural. Not to mention the Legend X also provides quite a good deal of detail and definition in the mid-range for being a god of thunder. Treble is a bit more vibrant and shimmery than the smooth but further extended treble of the Legend X. I enjoy both presentations so it will come down to either preferring one or the other or wanting a contrasting sound profile. The Legend X are still my favorite, but the ONYX is an awesome contrasting sound for the price. They truly work well together.



The single best word I can find to describe the ONYX is, “Flanker”. This sucker impressed me whilst coming from out of nowhere. The price and performance of the ONYX will undoubtedly redefine the $1000-$2000 price bracket, and it does so costing only $500 or so. It provides much of the performance, enjoyment, and quality that the much more expensive options do. This really allows those with a constrained budget or the financially responsible types to get into their music at the best bang for their buck.

I figured I would share the below images in all their glory since I took the time to compose them. I decided not to use them as the sole or main images because I didn’t want to misrepresent the product as being blue.



Last edited:
Love your interpretation of the midrange! Cheers!
Thank you. Your review was stellar. Quite an imaginative experience.
We both had a Legend X comparison. We also agree, and the LX has satiated my desire for a flagship. Nice review as well.


Headphoneus Supremus
Nothing Else Matters
Pros: Enormous soundstage with ample authority
Specific transient leading edge timbre and texture
Bass note resolution with complete (true to life) detail
Specific drum imaging and realizations
Harmonically real guitar creations
Ultimate pace and swagger
Bulletproof build and design
Incredibly revealing of source and file quality
Does some genres better than others
Cons: While natural and organic, not exactly vocal centric (maybe a good thing)
Not masterful of all genres, but insanely good with most
Even and complete frequency response, though some may EQ
Ever so slightly short nozzle length
Does some genres better than others
Super Super (1).jpg

I really want to thank Thibault for sending the ONYX in exchange for this review. I can totally get behind what the ONYX is doing; happy to join in the release hoopla!

Get em here. Sold only factory direct.


The EarSonics ONYX is incredibly revealing of source. Be it your amplifier, digital audio converter or song file......the ONYX simply replays stuff. This can be quite confusing as its bass and lower midrange are boosted, provided they are boosted in your song file. So it will not make your thin files sound better, but it will offer an incredible window into what’s provided with your audiophile playback. Note, this will take into account your amp personality, DAC personality and basically everything else in your signal-chain.

So try the ONYX from a phone and get its basic personality. But switch to an audiophile DAP or desktop and prepare to be floored. Strange but true, this is simply how it is.

Does the ONYX have a personality of its own? With-in the realm of playback the ONYX does bestow traits of its own. Yet those traits are so darn pure and admirable, they almost are not perceived as color; but ultimately they are!

So maybe the best way describe the bass here is to tell you what it’s not.
  1. It’s not poofy in any way shape or form
  2. It’s not thuddy or one dimensional
  3. It’s not omnipresent
  4. It’s not boring
  5. It’s not slow
  6. It’s not incorrect
  7. It’s not foggy
  8. It’s not fake
  9. It’s not distorted
  10. It’s not dry
  11. It’s not in the way
  12. And most importantly......it’s not wet
Every time I write the word “bass” I am not actually meaning just bass. That’s right. What I mean is the most visceral, deep-reaching, physical and timbre complex bass you have ever heard...........ever in your life.....bass. The best placed, best toned, most complete bass you or I have ever heard...............ever. It’s quite simply bass you do not know yet. It’s bass you can’t imagine. It’s bass that has to be heard to be believed.

Now the crazy part is I’m not exaggerating, I’m communicating. Does bass tone define the EarSonics ONYX whole signature? I mean is there still a balance...of sorts? Yes, and no.

Bass IS the first thing you notice upon placing them in your ears, there is no denying that. So…………the question that comes to mind is surely this must get old? Fun for ten minutes, but then you have had your thrill, and its overstayed its welcome? No............you never tire of this bass. In fact, you endlessly find new tunes to exploit and love. It’s just that good. The way the tone is integrated IS special. For the segment of folks reading that have already made up their minds about the ONYX………….that it’s too much.......I feel sorry for you.

While the ONYX sounds fine from a phone, they beg for more power. Also you will not appreciate their sound till at least 75 hours of burn in, full burn in at 100 hours. The ONYX is roughly 6dB more efficient than the IER-Z1R. So typically the WM1A/WM1Z Walkmans have just enough power on high gain for the IER-Z1R. 6dB doesn’t sound like a lot but it is. Try out a desktop amplifier to find the ultimate scalability. This was very surprising and the most up-scaling IEM I have ever heard. So they are efficient but keep getting better with better gear! The ONYX just keeps scaling up and up.

The bass tone and placement are so correct, how could any of this be bad? The bass is taken apart, delineated and re-introduced in such a way......we haven’t heard before. Due to the texture, pace and timbre, we are now in the presence of all we could ever ask for.

Much of the time it’s not truly the bass quantity but the bass quality that makes for this experience.


Could the EarSonics ONYX be too dark?
This is an interesting question? I mean……….I like darker signatures so? But before burn-in and mentally adapted, yes, it could seem too dark. It’s not forward (due to a forward midrange) also it’s not bright due to an overwhelming treble. So? I mean yes, it’s a slightly tilted response, yet totally comfortable and smooth. But still it depends what sound you are after? There are always going to be people looking for more of a flat reference sound, and we don’t have that here!

The Acclimatization:
(biology) The climatic adaptation of an organism that has been moved to a new environment.

It takes a while. That’s all I can say? Maybe 100 hours burn-in, and a couple days listening. So for any noobs there is a way out of the woods.

I mean we are always going to feel there is a give and take to IEMs. We are raised to believe you give and get. Even the tooth fairy gave you money, but took the tooth under your pillow. Still you get a lot with the ONYX and have to give up very little. It effectively plays 90% of my library better than I ever heard it.

The Treble Experience:
While never strident, it seems to walk that proverbial line where just a smidge more would be too much? So I guess you would say it’s perfect frequency wise. I mean this treble section is needed this way to counterbalance the bass.......and it does. There are obviously other IEMs which offer an embellishment in treble. This is not that way. Meaning the frequency is correct with no real bumps out of place. But where the embellishments are to be found happen with what the soundstage imaging does. So not everything goes way outside the soundstage, but when it does it’s fully surprising and accurate! The treble is not as harmonically enriched as some, but somehow this causes the ONYX to seem more accurate? It’s interesting too, as the technology has not been disclosed yet. I have no idea how this treble is made. Thus all the better in case of predisposition getting in the way. Obviously by this time this review is published I’ll know the technology.

The best part of the treble is how the correct rendition of elements fall outside the center. I’m pretty sure this is due to created correct phase? They are using Acrylic Heart technology, offering sound rigor and phase control. Plus TrueWave technology allowing optimal work on phase control, and a first-order “Magnitude Curve”. It’s also maybe the black background which is results in such a contrast between elements? To add to the effect, the transient response (across the board) is top level! When all of these attributes are placed together, the results are greater than the sum of each individual trait! Everything is totally cohesive and not one area of the treble seems like a bolt-on?

To get back to the dark background, it seems this is especially what’s going on when you hear small minuta arriving from a distance.

The Bass Experience:

Simply it’s real bass. It has all the factors of timbre and texture that you hear in real life. The ONYX sounds like bass guitar played live. The rhythm of the bass and how it interacts with the other constituents of the song is correct. If its bass by itself you seem to simply hear it clearer. You are closer to it, you understand its character better.

The Midrange Experience:
I don’t think the mids will let all that many people down. It’s the IER-Z1R mids in a way? So if the midrange didn’t work out for you with the IER-Z1R, well history is going to repeat itself. Really this is the IER-Z1R sound, if not better!

TA o1.jpg

Scale is everything, unless you don’t care about sound quality. Maybe you’re just interested in convenience? Whatever your value system is the ONYX has you covered. From a phone they don’t sound bad, due to their sensitivity. But get them a proper DAP or desktop, and they will surprise you. Bigger soundstage, more authentic instruments and better PRaT. Not only that but the desktop is the most natural way they sound. Interesting my TA does not offer EQ.......but really I don’t necessarily need any!

three 3.jpg

Is the EarSonics ONYX only for Rock and Metal Genres:
Absolutely not! While it does excel at Rock and Metal, the ONYX is much more well rounded than that. In fact if EDM was the only genre listened to, you would be right at home. Due to the same attributes that make it a winner for Rock and Metal, those same qualities carry directly over to EDM. In fact it may do EDM even better than Rock and Metal? Big synth washes and emotional breakdowns make the ONYX special. But it’s probably the over-all pace that makes it work, that and tone character? Nothing overlaps or is buried. Umwelt just happens (coincidentally) to be a French musician and one of the greatest Techno Artists. His work “Days Of Dissent” was used excessively to understand the limits and capabilities of the ONYX!

What about OSTs?
It’s not really a surprise that all of Hans Zimmer sounds incredible. John Williams is another composer that comes off clear, exciting and natural. Why? Due to the grand soundstage, true to life pace and instrument texture. OSTs are great! The ONYX seems to simply convey what’s in the recording. It’s just that if there is nothing stopping it, from unveiling what is there, if a heavy bass is lurking, that’s what you hear! That means if it’s a heavy Dub style, you get that.

Top side  (1).jpg

The EarSonics Company:
EarSonics was founded in 2004 by Franck Lopez, a musician and sound engineer who wanted more than he could find from off-the-shelf monitors. Eventually EarSonics split into two sides, offerings professionals high quality stage monitors, and our side, the audiophile side. Today EarSonics now offers a full line of CIEM as well as Universal IEMs. David Guetta, Elvis Costello and Johny Holiday use EarSonics monitors, to name a few. They supply nearly 90% of the industry in France.

EarSonics SAS
ZAE Via Domitia,
171 Avenue Des Gardians

Phone:+33 (0) 467 72 22 12

EarSonics makes/has made
The SM2 iFl, The Velvet, The Velvet 2 HR Edition, The S-EM6, The EM32, The ES-3, The ES-2, The ES-5, The Aero, The EM3-Pro and the EM64, just to name a few.

Besides new models introduced like the Acrylic Purple Pro, we are just starting to see EarSonics branch off into solid metal universals like the Grace Platinum, Grace and Corsa.....most interesting (for us here) are the recently introduced Blade and Stark EarSonics Hybrids.


As it seems that in many ways the Blade & Stark is our nearest kin.

The EarSonics Hybrid Monitors; The Stark and Blade have proportionally increased in smoothness with extended burn-in. The Stark and Blade have 8mm DD drivers. The Blade is the lower priced version with 3 drivers, the Stark has 5 drivers, respectively.

Close up 1 (1).jpg

Take note that for 50% of the review process I didn’t know what the ONYX was. EarSonics sent out review units not disclosing the cost or driver methodology. We were not allowed to share any impressions or anything until the release date on February 8th.

This, it turns out, was a great way to get started. Many times knowing how something makes music will give us expectation bias, actually changing the landscape. Here we had to estimate things. I started to try to guess the technology, then after e-mailing EarSonics and getting no answers, I simply forgot about the hows and whys and let the music take over. I will say that I was pretty confident of DD. Also after a week I was able by happenstance, to create driver flex. Yep, (only one time ever) my first week and only in the right ear. That pretty much answered part of my questions. Obviously bass like this doesn’t come from BAs.

Friday February 4th, 2022:
The Specifications have arrived from EarSonics: THE CAT IS OUT OF THE BAG! $561.00

This is a four driver hybrid design. One bass DD, 2 BA medium frequency drivers and single treble BA.

ONYX 122 (1).jpg

2nd full group (1).jpg

Final card copy (1).jpg

I sincerely wish to thank Jean Pierre Pinaud for his handy work!

encasement  (1).jpg

Take note, this is exactly how they are packaged. The IEMs are placed lower into the foam to protect them. The cable is attached and coiled into the carrying case which is partially zipped.

In The Box:

UnHR 4C cable 4 core (2 pin 0.78mm) (silver) 3.5mm
2 pairs of memory foam tips of different sizes
2 pairs of mono flange silicone tips of different sizes
2 pairs of bi-flange silicone tips of different sizes
1 cleaning tool
1 Carry case
Builder ID card

Metal black mat shell
Sensitivity : 122dB/mW
Frequency response : 10Hz-20kHz
DCR: 16.5 ohms
Drivers (QUAD)
1X dynamic bass
2X balanced medium
1X balanced treble


IEM Tips:
I ended with many various tips which seemed to work. The included foam tips fit well. Though I stayed using some white no-name tips in daily use. I ended placing them somewhat in the middle length of the nozzle and allowed them to “find” the spot where they could perform an air-tight fit. Also the tips stayed on upon removing the IEMs from my ear. The white tips where not seated at the total back of nozzle in daily use. Thus the nozzle opening was not pushed to the complete end of ear-tip on regular use. Surprisingly the original Sony Hybrid large tips worked very well also. Normally the diameter of the Hybrid tips nozzle opening will restrict treble and create a more bass heavy response. Though with the ONYX, this was not the case. Sony Triple Comfort tips did not work (neither gray or old school black). The clear silicone IER-Z1R Hybrid tips didn’t work-out that great either.

The nozzle (diameter) circumference is on the smaller side. This will mean that your choice of tips will always need to be smaller nozzle circumference. Even though the nozzle does not have an end-lip, narrow circumference tips should stay on. Like the original Sony Hybrids, regular size tips will work, but due to their inner nozzle circumference, are not optimal and will not necessarily stay on after removing the IEMs from your ear.

The included UnHR 4C cable worked well for much of my use. Though I ended with the 4.4mm HanSound Zen 4 wire in daily use. Even using the included UnHR 4C cable did show an improvement in quality in desktop use, but 4.4mm was simply better.

This is maybe the most important part of the review, as if you don’t have fit, you can’t hear the IEMs correctly. The metal bodies of the IEM are large, though they are wonderful to wear. They are not cold, but have a great feeling in the ear. The ergonomic build really comes through in daily use. I found the ONYX to stay in place and not ever even change frequency response when I placed my finger on the outside when they were mounted in place in my ear. This finger test means that the response is consistent and you have achieved optimal placement for tone.


This shows a subjectively chosen list of IEMs I own or have heard in an order of less bass to more bass. Only the amount of bass is listed. Things like bass detail and technicalities are not listed in order. This is useful only as a guide to understand bass quantity. The only two on this list I don’t have near by for reference are the 64Audio N8 and the qdc Anole VX; the rest are accessible on-hand through ownership. The IEMs below the surface of the water exhibit a deeper bass response than neutral.

Comparison To The Sony IER-Z1R:
The EarSonics ONYX is about 6dB more efficient than the IER-Z1R. The ONYX is kinda like IER-Z1R in tone. While the IER-Z1R offers a slight smoothness over the ONYX, the ONYX offers vibrant imaging, separation and detail. That detail, imaging and separation is in the midrange and the bass areas, especially.

This is tough:
THE ONYX IS BETTER THAN THE IER-Z1R. So.............that’s a pretty big statement I know? But it is what it is. I had previously guessed this but it took side by side tests to totally confirm it as a reality. I don’t have a way to electronically verify the volume difference or equalize volumes, but I feel fairly confident in these statements. In many ways it’s rather amusing how similar they are!

So if you already have the IER-Z1R, would it be advantageous to get the ONYX? You don’t need two IEMs with very close to the same tune? But fit is something totally different between the two. So for those who for whatever reason didn’t get the IER-Z1R to fit but loved the sound, get the ONYX.

But if you have money to burn and really want a variation of the IER-Z1R (more on that in a minute), by all means go ahead and get it.

With the ONYX being roughly 6dB more efficient than the IER-Z1R, it theoretically gives you the ability of playing with more virtual damping factor? That said, if your DAP is on the border with power for the IER-Z1R, the ONYX is a better choice.

To tell you the truth, it’s really hard to compare two IEMs which when volume is adjusted are almost equal. Though I think the IER-Z1R is slightly less stark. The ONYX seems to exhibit a slightly brighter midrange and slightly better vibrancy across the playback spectrum. I can’t totally tell you if one is superior or not, as that MAY be subjective? If this vibrancy is wanted or not would be the choice of the individual. But…….I like the ONYX more!

It really boils down to specific tone. Meaning even though they have similar characteristics; the ONYX colors the instruments a different color. I know this is a strange statement but....

What is unique about the ONYX is guitars (as only one example) they have a slightly darker aspect across the board. So you are probably thinking that since the tone is different than the IER-Z1R that it must be off, but it’s not. That is the magic actually. Everything sounds totally correct, but there is a completely different feeling at times to the instruments. In a way they are more detailed and have a unique tone that sounds right? Also there is a slightly different soundstage if you try and compare both. It’s amazing as you wonder how two IEMs can be the same and different yet both also be correct? But they are! And it’s not exactly like someone changed a slider on a mixing board during the mixdown. These differences are deeper than that and are an intrinsic way the whole instrument sounds. It has you saying “I have never heard the instruments sound like that?” Yet it is not wrong at all. So it almost takes you to the point of questioning everything. What I’m saying is these tones are like hearing the instruments (in a way) for the first time.

I’m also still waiting for this phenomenon to get old, but I don’t think it will.

I have never heard a response character like this? Yes, in many ways it’s like the Sony IER-Z1R, but also something very fresh and unique. It’s that uniqueness that has you coming back over and over again. You are simply reconfirming what you heard the day before, because you almost can’t believe it was real! I guess in basic terms you would call this tone special. Still it goes against many ideas of audiophile playback being one single way? What happens is you hear it, and do a double take. As normally something that’s a departure from the norm is not acceptable, but in this case it is.

How can the IER-Z1R and ONYX both have the correct tone response?
The original musical event was lost in time. It’s gone, we don’t have it any longer. There in-fact is no way to recreate it. We can’t recreate it as it was not there (recorded) in the first place. It’s not some narrow restricted set of frequencies which will then recreate it, as there is nothing to exactly recreate from the file. Instead there are interpretations of what it could be. Those interpretations can actually be many things. The only thing that’s important…………..is if you can partake in the illusion. If there is communication of the emotional elements of the musical event, then the IEM serves it’s purpose.

The tonal response terms of even, complete and correct are in truth very abstract ideas to reach IEM success. Terms like accurate and true to life, actually have way more leeway than you might expect.

This is by no means saying the ONYX is following the Harman Curve. This is simply showing how a group of listeners can agree on a tone.

No recording studios are standardized throughout the world. Every studio uses a different set of monitors for mix down and they each have unique sound characteristics. What that means is there is no baseline for reproduction in speakers or headphones. So? Everyone is guessing as to the reproduction of the actual tone in recorded music. Sure, there are still better and lesser reproductions of tone, inside the “circles of confusion”.

This results is many different responses as being correct. Below is a test by Sean Olive. Even though reproduction varies, the transducer quality can still be quantified.

All the groups agreed on the relative ranking of products. (Olive, JAES, pp.806-825, 2003)

Categories Of Listeners:
  1. Selected and trained (about 95%) 12 people
  2. Retail sales (about 39%) 215 people
  3. Audio reviewers (about 20%) 6 people
  4. Brand sales and marketing (about 15%) 21 people
  5. Students (about 5%) 14 people
A test using 350 people, among them were the above 268 people. A judge of performance by listener.

Floyd Toole said,

“Humans are amazing measuring instruments.”


“I mean, I’ve done this for forty years, and I still kinda say........Wow, this is remarkable.”

“Because, as I say, you’re listening to strange music, in a strange room, with strange loudspeakers; and you’re forming opinions.”

“The only way to get those consistent opinions out of you, is to not know what you’re listening to.” “Do it blind.” “If you know what you’re listening to, I don’t care what you think.” “It doesn’t matter.”


Undoubtedly……..if the IER-Z1R is a Akira Kurosawa movie, the ONYX has to be the Luc Besson movie!

The other descriptor that is fitting is lushness. Yep, in case you wanted one more word to help understand what is going on, that sums it all up! Now the interesting part of “lushness” is typically we trend to think of less resolution or cloudiness, maybe? No, that’s not exactly what’s happening here. It’s more liken to a pleasure of the senses thing? Think French cooking like Pâtisserie. The ONYX is a dessert.

64Audio N8 Universal:

I have to admit I don’t own the N8, and the unit (I heard) was a universal demo to be used to order customs from. I also have been informed that the CIEM N8 have even more bass. So this direct comparison is only from memory. While the overall instrument balance was similar I don’t remember the soundstage being as big as the ONYX? Also the bass and drums didn’t offer our extreme detail as the ONXY seems to convey on a regular basis. I really liked the N8 but felt the bass was somewhat crude, even though plentiful? Still it was a very “analog” sounding IEM. Take my comparison with a grain of salt, and rest assured the two will be compared side by side often by others.

qdc Anole VX Universal:
Another I don’t own, but I have a very clear memory of what it is in-fact! The two are pretty much complete opposites. Really this is a great one to explain what the EarSonics ONYX is....by contrast.

Some may if fact find the treble too hot on the qdc, a character trait which is not present with the ONYX. The qdc Anole VX is kind of clinically doing everything right, yet doesn’t exude any single aspect with flamboyant confidence? Where the ONYX has a healthy dose of panache! The BA set-up has all the bases covered as far as midrange and treble. Though you know with-out guessing the ONYX bass is more detailed and emotional. The Anole VX brings a lot to the table, and our VX tune is maybe more mainstream than our ONYX, though I’m not so sure? Both are so very different they are not really comparable?

Sony XBA-Z5:
In so many ways the Z5 is beat at its own game! Bigger bass, bigger soundstage, bigger imaging...........bigger everything. I can’t help but still hear a relationship between these two. They approach music from the same ideas. Still.......I guess this (of anything) shows the 2014 XBA-Z5 as dated and owning ineptitude on all fronts. It’s probably because at it’s soul the ONYX is attempting to better exactly what the XBA-Z5 does. Only here is progress in areas not even dreamed about. The ONYX effortlessly showing big drums and bass as detailed and refined subjects of substance and emotion. It wipes the floor with the Z5. Doing everything it does many times better. Besides that, the ONYX imaging is icing on the cake! Even the ONYX midrange showing beautiful and showcased vocals, the one attribute the XBA-Z5 struggled with. And if you tried to work with the XBA-Z5 and lift-up the mids, you didn’t like what you found waiting! Here with the ONYX......adding very small amounts of EQ goes to find alignment in the midrange if needed.

Really I look at the XBA-N3 as the little brother of the XBA-Z5. It’s the same comparison. The ONYX wipes the floor with the XBA-N3.

Bass Is Subjective:
First off how many reviewers have judged an IEM as inept due to bass character? Really this subject is difficult as it’s hard to be totally objective at times. In reality every reviewer is only trying to be objective, we are ALWAYS referring to something in the past to gain perspectives as to what we are currently listening to. But we see it all the time; reviews which end up critical of an IEM due to a failure in some bass quantity/quality. Probably in a perfect world the bass would end up like real life? It wouldn’t color any instruments and would stay behind the scenes until called for.

When introduced this bass would emulate life. This bass would have all those things you have come to really enjoy about live music. It would have tone, timbre and separation from nearby frequencies. The texture in effect is just that, an added dimension which goes further to delineate the bass from other nearby frequencies. So it of course is not the quantity but the quality of bass. But let’s go one step further. What would happen if there was a slight increase in quantity as well as quality? What if the ability went to the next level? What if the bass was not only more real but was real due to texture, timbre, relief and delineation? That’s what we have with the ONYX, a new and previously unknown bass experience! This style of playback would at first appear impossible, but EarSonics has made it possible.

What the ONYX ultimately teaches us is variation. There would be different amounts and character in bass tones, but until you hear it, you have no idea how infinite it is. Now we can approach bass leads and hear the emphasis and filagree placed-in as an extra detail. Whole bass lines are now emphasized and separated from what was once simply just a bass tone and buried in the mix. There has always been bass leads but often they have taken 2nd place to the regular guitar leads and vocal elements. Now the bass doesn’t have to only support the rhythm section; a strong reproduction ability will actually unearth whole new levels of creativity, never before heard, except in live replay.

ONYX Detail final (1).jpg

Room Response:
There is something called room response. Or better yet, room response simulation. Normally stereo speakers will have a slight low-end bump due to room response. This is the result of sound energy bouncing around inside the speaker cabinet walls. The energy gets sent off the rear and sidewalls of the speaker and results in bouncing off the rear & side listening room walls, directed back towards the listener. The energy is combined with whatever regular response comes off the front of the cabinet. Such a phenomenon is also always present in night-clubs and live performances when music is played. Typically this style of sound is what separates headphone tone from live music.

Being able to recreate the room reverberations is critical in getting a believable tone from a IEM. The only issue starts with the listener, as he or she is now asked to believe. It’s critical to acceptance of an IEM tone if this set of frequencies is not noticeable. Typically our brains filter much of this out in a live setting. We hear it but consider it non-important. Probably much of brain burn-in is connected to learning to ignore this phenomenon in IEMs, especially with the ONYX. It’s one of the first things you notice upon hearing the ONYX, yet slowly diminishes until you’re fully acclimated.

Typically room response simulation doesn’t effect fidelity unless it creeps into the pace and rhythm area. This is often a double edge sword as it’s needed for body, but can seem to infringe on the space between notes. Not only note fall-off, but the critical attack impulse. Many striving to seek balance in this area are the Sony XBA-Z5, XBA-N3 and the IER-Z1R.................and of course our EarSonics ONYX here.

So even though these are slightly bass head IEMs, there is nothing boomy or smeared. The notes have body.....but nothing is blended. Everything is separate and has its own tone, timbre and texture. This is why the bass is so real. Also there is an interlocking affair with the drums. This is how pace is created. Because all that was just described about the bass is also going on with the drums.

DSC_0029 (1).jpg
DSC_0009 (1).jpg
Detail 3 (1).jpg
Detail 2  (1).jpg

I can’t help but realize these were made by a man who plays bass……….but fully aware of the dependence upon drum timing. Why else would we hear the drums in perfect clarity? The drums are for lack of a better word simply real.

Back (1).jpg

The ability of music to somehow find its core groove. This results from capturing and replaying the subtle nuances that make timing and pace special.


Hans Zimmer
The Dark Knight Rises: OST 192 kHz-24 bit

There are very few perfect things in audio. Sure, there are perfect experiences. Jimi Hendrix was talking about an experience too, but I don’t think it was audio.

With this style of soundtrack, Hans Zimmer has done what everyone who makes OSTs attempts to do; connect the images with emotion. To carry the emotion of the story to the next level. But somehow after seeing the movie, the soundtrack now by itself is stronger? And stronger again hearing it with audiophile clarity, especially matched with the ONYX. It is almost that you don’t need the movie anymore. Thus music in the OST genre being taken to the next level. Maybe this is always the case with soundtracks? Still this one seems much more emotional?

This is Batman’s IEM! And......with this soundtrack it’s absolutely perfect. Perfect in every way, shape and form. First off, look at the IEM. Does it look like Batman’s only IEM? Of course it does. This IS the Batman IEM!

Sonically we have just entered the whole realm of the Dark Knight! There is a breadth and scope here that only this IEM can provide. Song 2...”On Thin Ice” slowly graduates to a climax, yet before it does it offers a sadness of emotion fully outlined by the strings. At the end of “On Thin Ice” starting at the 2:17 minute mark is the strings. This dovetails into “Gotham’s Reckoning” a song filled with drama. Our bass is exemplified right from the start of it. It’s tactical and real, you can reach out and touch it! Besides the spoken chorus, a wonderful almost whispered affair.......things get going at the 2:35 minute mark. The drums are emanate and clear. And again another seamless transition into “Mind If Cut In?” The piano theme is weighty and echos.....but then at the 2:06 minute mark the bass drops! Glorious and full, 3D and omnipresent. This is life and we are alive! We are in the moment, nothing else matters.

What? “Underground Army” is here. Interesting as this song offers a “rhythme” that has angularity. A syncopation that’s shifting and obtuse? Just the fact that it is slow to understand makes it all the better once it falls in place. Finally counterbalanced with “Born In Darkness” we have some light? As apparently contradictory as that sounds...........everything has a place and is displayed just as it was created to sound! The EarSonics is in its element. Nothing is left out, yet what is added holds the moods and emotion of the event. At the 2:44 minute mark “The Fire Rises” there is nothing more than violins being plucked, yet they are not violins as we know them to be.....no.....they are sound elements, abstract and formless. There is a slight distortion as the recording can’t capture all the elements with faithful intensity, so it simply does what it can. “Nothing Out There” at 42 seconds brings in abstract sounds......almost like crows. They fly across our audible landscape to be scooped up by the reoccurring piano once more. And again the strings.....the strings showing us the way. Really this soundtrack is held together with strings, even though they are not always present. “Fear Will Find You” starts out and shows it’s not all bass tone, but I have a feeling it’s setting us up for more? Then the second half comes through. “Why Do We Fall? Finally reintroduces our theme.........but with added energy. A more mature evolution just like I suspect the ONXY is parlaying over it’s younger brothers, the EarSonics Stark and EarSonics Blade, even though I’ve never heard them. I can guess?


Dead Can Dance
Into The Labyrinth (Remastered)
“Yulunga” (Spirit Dance) 88.2 kHz-24 bit

Lisa Gerrard’s vocals are all you could ever ask for. One thing special here is the side to side panned rattles. You can only imagine the complete obsession with tone that beholds DCD fans. Most DCD fans are very well versed on the music. And the ONYX takes them where they want to go. The reverberations are spot-on with Lisa Gerrard’s voice. The fact that everything is correct. The ebb and flow of the album takes place with-in the intended boundaries. Really.......I have never heard the bass in this played exactly this way. It’s primal and authentic. The 2.07 minute mark drop can be bewildering for beginners! The showstopper and instantly accessible quality of this song make “Spirit Dance” the perfect demo.....into the world of the ONYX.


Mick Gordon
Doom Soundtrack (2016)
“At Doom’s Gate” 48 kHz-24 bit (USB keycard)

This has often been the ultimate test of an IEM due to the high tech recording and relentless musical style. “At Doom’s Gate” shows some of best the ONYX has on offer. We are greeted by heavily layered music which the ONYX takes apart with ease. Probably the best part is the visceral attack and soundstage, showing every ounce of authority present. This takes the cake as I’ve never heard this song replayed quite this way! There are all kinds of elements here that most IEMs seem to have difficulty in separating? Here we find the ONYX tour de force!


Black Sabbath-Black Sabbath 1970 (Remastered)
2002 Victor (JPN) VICP-61710 44.1 kHz-16bit

This comes to life with the ONYX. One key factor here is replay timbre; the ability to hear a difference between the tone of the guitar and bass playing the same notes. Add to that the great live drum sound.

First off, many are critical of this first album being recorded with a substandard quality? It’s not true. The band are totally familiar with this material. They played these same songs over and over again in a live club setting before finally making into the studio. Maybe what is simplistic is basic tracking, where elements are not ornate or polished? Still now with the ONYX the reality of playback takes place. Instruments don’t have to have anything extra because now we are witnessing the sound as closer and of its true nature. What I love is how the guitar has this unique tone. And truly if you listen you can tell where they did multitrack to bring a fullness to the sound. Geezer Butler’s bass is insane. Behind The Wall Of Sleep is mind bending! You can hear every little embellished bass emphasis. Everything! The fact that the guitar and bass are separated and the bass is in the middle. I’m speechless really?

Ozzy is front and center clear as day! Any questions about vocal replay can be put to rest. The special tone of the guitar as it reaches the climax of this song! It’s darker a little but actually normal, just the continuously new way the ONYX does guitar. It has a thicker and deeper tone, but it’s normal, just new? And all the room reverb, it’s not distracting but adds to the recreation of the “live” sound. And I’ll end this and say that it’s probably that fact that this playback is all so close and a factual.

We are drawn into a kind of one to one with the playback. It’s real, and near. It’s big, bigger than you can imagine! Perfectly separated into all of the key elements. And those elements have life! It’s not a 1969-1970 recording anymore, it’s being played for the first time right now!


The Cure
Faith (Remastered)

“All Cats Are Gray” 44.1 kHz-16 bit

Finally we end with some “comfort music”. The important part of this is again electric-bass tone, but also how everything else is put on-top. I’ve been listening to this since its release in April of 1981. The electronic drums are clear as day. There is a recording artifact at the 9 second mark; it’s maybe a microphone-cord or dirty knob-twist. The 1/6th of a second “buzz” is shown in perfect resolution. The best thing here is the balance.....the balance of every part of the song. Nothing is out of place. The cymbal splash at 2:10 minute mark means on the very next cymbal splash Robert Smith starts singing. These cymbals are higher pitch than natural and electronically processed as they are supposed to be. The main theme is the keyboards, coming-off understated yet present throughout the entire song. The songs mood is from the keyboards primarily. While the keyboards are two, each occupies its own area of the head-stage, with the left dominant and louder and the right of a higher pitch. It’s really the same synthesizer preset for both, yet the variations are golden. The second and maybe most important feature is the continuous electric-bass line. The bass is the songs foundation yet with subtle emphasis changes. The ONYX has the ability the show just how different that emphasis is. Smiths voice is almost lackadaisical, but if you listen very carefully it’s not. There is a slight room reverberated echo to his singing, and the fact that the second verse is sung way more direct. Also it’s quite interesting that his voice is multitracked too. A progression into silence as the piano plays....and the song ends..........

The Secret:
If you have made it this far in the review, I congratulate you. But also I will bestow the single secret to understanding the ONYX.

Sound signature success (with the midrange) only happens at certain volumes. Is this a deterrent to the IEM? Yes and no.

The issue is the midrange will only surface at a certain volume. That means these are not low volume listening IEMs. The ONYX is a medium and higher volume listening IEM. Unless of course if you enjoy the character of the ONYX at low volumes, then OK? Frequency graphs may only give us clues to the complete perceived tonality.

The Four Curves:
  1. The ONYX true sound signature. (what they emit in reality)
  2. The ONYX personal to you sound signature. (depending on ear anatomy and hearing physiology) This is what you hear.
  3. The ONYX tested frequency response graph. (the machine)
  4. The ONYX specific sound character in response to volume used. (Depending on volume level chosen, a different midrange response)

So you can see there are actually four individual frequency responses, though only one is measurable. The wild-card here is replay volume used.

Frequency Graph Representations may pose a challenge to truly understanding the ONXY midrange.

I’ve come across this before with one other IEM, and three full-size headphones. This is nothing new, but in a way rare; confusing to those who don’t find the tonal response to match the group understanding. In simple terms it just means you will need a certain volume to get into the midrange. Too low and everything will sound foggy and dark. At optimal volume the ONYX will come alive.

And Finally:
The 6dB difference in efficiency between the IER-Z1R and the ONYX is a conservative estimate only. This means that it could in reality be a 8dB or 9dB difference. That in reality the ONYX is maybe 9dB more efficient than the IER-Z1R?

Regular Disclaimer:
This is a single reviewers experience, your results may vary.

Normally an IEM has first-impressions. In this case really after-impressions are much more pertinent. Normally though-out the photography sessions I’m very careful not to scratch or break the IEMs I’m working with. Amazingly after a while I came to realize just how tough the ONYX was built. After maybe 7 cable changes I came to find the 2-pin very robust. I also started to realize just how bulletproof the actual IEMs themselves are, never showing any scratches, paint-chipping........or discoloration in the handling process. They are some of the most robust products I’ve come across.....ever.

After full burn-in and realization that volume truly delegates the tone, I found myself continuing to find old music to become new. There was always albums that I suspected had bass lines but I could never hear them in such delineation or clarity! All and all I’m still being surprised at the ONYX and wonder if it’s still getting better and better? The ONYX is a special product that breaks preconceived notions of what is possible with an IEM in 2022!

Equipment Used:
Sony WM1Z Walkman DAP MrWalkman Firmware 4.4mm/3.5mm
Sony WM1A Walkman DAP MrWalkman Firmware 4.4mm/3.5mm
Sony XBA-Z5 Universal IEM 4.4mm Kimber Cable
Sony XBA-N3 Universal IEM 4.4mm Stock Cable
Sony TA-ZH1ES DAC/AMP Firmware 1.03
Electra Glide Audio Reference Glide-Reference Standard "Fatboy" Power Cord
EarSonics ONYX Universal IEM
UnHR 4C cable (4 core)(2 pin 0.78mm)(silver) 3.5mm
HanSound Zen 4 wire 4.4mm cable
Sony IER-Z1R Universal IEM 4.4mm stock cable
Sony Walkman Cradle BCR-NWH10
AudioQuest Carbon USB

Apple iPhone


I try and review IEMs emotionally. The goal is to learn how close I can get to favorite my tracks. Using this method will often result in thoughts and ideas that are hard to describe. It may be easier to use a template of words and processes, but that’s boring. I’m trying to communicate these ideas another way as much of the time my own concepts/adjectives simply sound better to me? I choose to use the word emotion here as the realism of playback has no way to be verified. There is no reference to what was recorded and saved as a musical document. The only thing we can possibly get IS emotion as the actual moment of the recording has been lost. What has been replaced as a music file is a new artistic creation, maybe better than the original, but none the less different.

After hearing Koss headphones against the Sennheiser HD 414 in 1975, I already knew Koss closed-backs were better for listening to Iron Man. So you could say I’ve been comparing headphones back to back since the mid-70s.

Growing-up with a baby-grand in the living room and my Mom a piano teacher, I refused to take lessons. Her record collection introduced me to The Moody Blues, Rod Stewart, James Taylor and the rest of the regulars found on 1970s FM radio. I took away her steam when she thought she was introducing me to Led Zeppelin for the first time. Not the actual band members of course, but Led Zeppelin Two on vinyl, and actually the song “Whole Lotta Love". I have somehow been into Zep since I was 12.

Her greatest collection was rare Gibson acoustics and small batch made luthier flat-tops which she inspired me to play!

What does this have to do with headphones? I’m not sure?

My biggest learning experiences were from making a wrong purchase. I tried to make the AKG k701 work-out and it almost did after a year of forcing myself to enjoy it. The AKG k701 taught me another sound signature I could relate with. IEM frequency response (overall tone) is probably 80% of the path to win-win. Today…..I’m able to like a whole bunch of sound signatures. Yet inside of that “tune”……the FR, timbre, positioning, detail and pace need to be closer to correct to value the IEM high.

In the world of IEMs there are values, well-rounders, one-trick ponies, overpriced values and overpriced rip-offs. Still, I’m always trying to make stuff workout by finding the good aspects of a monitor. Where some reviewers use only the included tips and cables, I’m trying to emulate the enthusiast who would be curious if improvements could be found near by. Often different than included cables I seek, different tips also……… to try and look for correction where I think it could be found. While I’m not positive burn-in is real, it’s just a method of being complete.

Typically I start out with soundtracks at first. I use soundtracks as they seem to be the best recordings of real instruments that I own. Typically with-in these soundtracks will be positioning I know, timbre I am familiar with, as well as soundstage transients I’ve become to know. I’m probably most impressed by the sheer size of the experience, so I look to find that in recordings. There are small instrument tones that I use to help me focus on replay character. The image as well as its placement in the stage can be either heard in brilliance or lackluster with all faults noted simultaneously. I have songs with a bass tone that helps find the limits of the bass ability.

When I switch to another music genre it seems there are paths to know if an IEM is well rounded or simply does a few genres correctly. Most success is from an even and correct frequency response. Timbre and tone, technicalities and the less tangibles all come together within the best examples. Yet in experience, there are no perfect IEMs to be found, only better and lesser examples of the art. The most difficult thing is simply missing an example of a major fault due to keying in on the great aspects. The simple way to learn is just taking the time to explore. Eventually that IEM that has issues will become exposed and noticed. The best and easiest way I know is actually by using the smallest grouping of music that that I’m most familiar with. The flip side is that music could actually be stale and boring so there is nothing wrong with using new music to simply get an idea of the entertainment factor.

Accurate - The music is (as much as possible) unaltered by the recording or playback equipment.

Aggressive - Forward and bright sonic character.

Airy - Spacious, typically referring to upper midrange and treble.

Ambience - The overall impression, feeling, or mood evoked by an environment or acoustical space, such as the performance hall in which a recording was made.

Analytical - Detailed.....typically thought of as neutral or bright.

Articulate - The overall ability to offer fast transients and efficient imaging of instruments.

Attack - The leading edge of a note and the ability of a system to reproduce the attack transients in music.

Attack (2) - The time taken for a musical note to reach its peak amplitude eg. notes will tend to sound more defined rather than blended with other notes.

Balance - Usually the tuning of the earphone. A well-balanced headphone would not have one particularly dominant frequency, but rather all would be “balanced.”

Bass - The audio frequencies between about 60Hz and 250Hz.The lower end frequency of human hearing. Bass can be measured in quantity (heaviness) and quality (clarity). Other bass descriptors are “muddy” and “boomy.”

Basshead - Emphasized Bass.

Bloated - Excessive mid bass around 250 Hz. Poorly damped low frequencies, low frequency resonance.

Blurred - Poor transient response. Vague stereo imaging, not focused.

Body - Fullness of sound. Substantialness of response.

Boomy - Excessive bass around 125 Hz. Typically edging into midrange and affecting pace.

Boxy - Having resonances as if the music were enclosed in a box. Sometimes an emphasis around 250 to 500 Hz. Often called cardboard box sounding, like boxes used as drums.

Breakup - When different points on the surface of a diaphragm begin to move out of sync, causing distortion. Breakup often occurs in dynamic drivers at high volumes as forces on the diaphragm increase. Breakup is less likely to occur at lower volumes or in planar magnetic or electrostatic headphone drivers.

Bright/Brightness - Boost in the upper frequencies or upper-mid range. Brightness is a feature enjoyed by many but walks a thin line to becoming unpleasant depending on the individual.
Brilliance - The 6kHz to 16kHz range controls the brilliance and clarity of sounds. Too much emphasis in this range can produce sibilance on the vocals.

Clear - Transparent.

Closed - A closed-in sound lacking in openness, delicacy, air, and fine detail usually caused by Roll-off above 10kHz; in contrast to Open.

Congestion - Poor clarity caused by overlapping sounds. Congested sound signatures lack detail and clarity, making it hard to hear separate instruments and may also be called muddy or muffled.

Coloration - The effect of a device on the music signal. The opposite of “neutral.” Various aspects can affect the tone, responsiveness or the frequency response of the music/audio.

Crisp - Clear.

Dark - A tonal balance that tilts downwards with increasing frequency. Opposite of bright. Weak high frequencies.

Decay - The fadeout of a note as it follows the attack.

Definition (or resolution) - The ability of a component to reveal the subtle information that is fundamental to high fidelity sound.

Delicate - High frequencies extending to 15 or 20 kHz without peaks.

Density - I personally started to use this word to describe note weight, and note authority.

Depth - A sense of distance (near to far) of different instruments.

Detail - The most delicate elements of the original sound and those which are the first to disappear with lesser equipment.

Detailed - Easy to hear tiny details in the music; articulate. Adequate high frequency response, sharp transient response.

Dry - Lack of reverberation or delay as produced by a damped environment. May come across as fine grained and lean. Opposite of wet.

Dynamic - The suggestion of energy and wide dynamic range. Related to perceived speed as well as contrasts in volume both large and small. Still in the end this word has many interpretations.

Edgy - Too much high frequency response. Trebly. Harmonics are too strong relative to the fundamentals. Distorted, having unwanted harmonics that add an edge or raspiness.

Euphonic - An appealing form of distortion that generally enhances perceived fidelity, often ascribed to the harmonic elaborations of some valve amps.

Fast - Good reproduction of rapid transients which increase the sense of realism and "snap".

Focus - A strong, precise sense of image projection.

Forward(ness) - Similar to an aggressive sound, a sense of image being projected in front of the speakers and of music being forced upon the listener. The opposite would be “Laid-back".

Full - Strong fundamentals relative to harmonics. Good low frequency response, not necessarily extended, but with adequate level around 100 to 300 Hz. Male voices are full around 125 Hz; female voices and violins are full around 250 Hz; sax is full around 250 to 400 Hz. Opposite of thin.

Grainy - A loss of smoothness resulting is a loss of clarity and transparency.

Grunt - Actually a guitar term intended to denote an authoritative and fast low end frequency response ability in hollow body jazz guitars.

Harsh - Too much upper midrange. Peaks in the frequency response between 2 and 6 kHz.

Highs - The audio frequencies above about 6000 Hz.

High Midrange (High Mids, Upper Mids) - The audio frequencies between about 2kHz and 6kHz.

Imaging - The sense that a voice or instrument is in a particular place in the room. Directly measured with square wave graphs and indicates transient edge response quality in the time domain.

Impedance - Indicates how much power is required for the driver. The higher the impedance, the more power is required to get the maximum quality and volume of sounds out of the driver. Electrical resistance to the flow of current in an AC circuit. The higher the impedance of the headphone, for instance, the less current will flow through it.

Layering - The reproduction of depth and receding distance, which audibly places the rows of performers one behind the other.

Laid-back - Recessed, distant-sounding, having exaggerated depth, usually because of a dished midrange. Compare "Forward".

Layering - The reproduction of depth and receding distance, which audibly places the rows of performers one behind the other.

Less-Tangibles - Everything other than FR, hence reverberations, texture, instrument timbre, soundstage etc…..etc.

Liquid - Textureless sound.

Low-Level Detail - The subtlest elements of musical sound, which include the delicate details of instrumental sounds and the final tail of reverberation decay.

Low Midrange (Low Mids) - The audio frequencies between about 250Hz and 2000Hz.

Lush - Harmonically complex, typicality thought of as thick with many additives. A rich tone and usually with some warmth to the overall presentation.

Metallic - Typicality an overall sheen which can become part of an off timbre response.

Midrange (Mids) - The audio frequencies between about 250 Hz and 6000 Hz.

Musical (or musicality) - A sense of cohesion and subjective "rightness" in the sound.

Nasal - Reproduced sound having the quality of a person speaking with their nose blocked. Closed off; a measured peak in the upper midrange followed by a complimentary dip.

Naturalness - Realism.

Opaque - Unclear, lacking Transparency.

Open - Sound which has height and "air", relates to clean upper midrange and treble.

Pace - Often assoc. with rhythm, a strong sense of timing and beat.

Physicality - Weight and realness, typicality used (by me) to describe bass, but can carry over to all frequencies. Female and male vocals could have physicality, if they sound real.

Piercing - Strident, hard on the ears, screechy. Having sharp, narrow peaks in the response around 3 to 10 kHz.

PRaT - Pace, rhythm and timing.

Presence Range - The presence range between 4kHz and 6kHz is responsible for the clarity and definition of voices and instruments. Increasing this range can make the music seem closer to the listener. Reducing the 5kHz content makes the sound more distant and transparent.

Presence - An emphasized instrument response around 5 kHz for most instruments, or around 2 to 5 kHz for kick drum and bass.

Punchy - Good reproduction of dynamics. Good transient response, with strong impact. Sometimes a bump around 5 kHz or 200 Hz.

Range - The distance between the lowest and highest tones.

Resolution - The clarity to separate and delineate musical information.

Reverb - Short for reverberation. A diminishing series of echoes spaced sufficiently closely in time that they merge into a smooth decay.

Rich - See Full. Also, having euphonic distortion made of even order harmonics.

Roll-off (Rolloff) - The gradual attenuation that occurs at the lower or upper frequency range of a driver, network, or system. The roll-off frequency is usually defined as the frequency where response is reduced by 3 dB.

Round - High frequency rolloff or dip. Not edgy.

Rhythm - The controlled movement of sounds in time.

Shrill - Strident, Steely.

Sibilant - The high unpleasant peaks that are usually unpleasant to the ear if too prevalent.

Sizzly - See Sibilant. Also, too much highs on cymbals.

Smeared - Lacking detail; poor transient response, too much leakage between microphones; poorly focused images.

Smooth - Describing the quality of sound reproduction having no irritating qualities; free from high-frequency peaks, and relaxing to listen to. Not necessarily a positive system attribute if accompanied by a slow, uninvolving character.

Sound Signature - The unique intrinsic sound quality of a headphone, music player, DAC, or audio cable. Some audio products emphasize the higher treble ranges while others strengthen the bass. This overall sound profile of audio devices helps audiophiles fine-tune the listening experience by pairing the right headphone cable, DAC, or music player with their headphones.

Soundstage - An illusionary effect of headphones to produce a listening space front to back, up and down and right to left.

Speed - Pace and timing, can have relationship with overall “tune”.

Steely - Emphasized upper mids around 3 to 6 kHz. Peaky, non flat high frequency response. Metallic.

Strident - See Harsh, Edgy.

Sub-Bass - The audio frequencies between about 20Hz and 80Hz.

Sweet - Typically reference to smooth comfortable high pitch sounds.

Technical Ability - A blanket term for attack transients, imaging, decay, tonality, tonal balance, timbre, temperature, and texture. At times overall frequency response (if even and correct) is considered part of technical ability.

Swagger - The ability of music to somehow find its core groove. This results from capturing and replaying the subtle nuances that make timing and pace special.

Synergy - The interaction or cooperation of two or more audio components in an audio system, which, when combined produce a combined effect greater than the sum of their separate effects. Example: the synergy between a DAC and a headphone amp.

Texture - The timbre of multiple instruments playing together, though more accurately the instrument “voices” together.

Thick - Typically bass or lower midrange density.

Thin - Fundamentals are weak relative to harmonics; bass light.

Tight - Good low frequency transient response and detail.

Timbre - The tonal character of an instrument which separates it from other instruments of the same tone.

Timing - Tempo in relationships with clarity of pace.

Tinny - Thin harmonically narrow, metallic, in treble region.

Tone - The sound of definite pitch.

Transient - The leading edge of a percussive sound, though the term can be applied to any wave form.

Transparent - Easy to hear into the music, detailed, clear, not muddy. Wide flat frequency response, sharp time response, very low distortion and noise. A hear through quality that is akin to clarity and reveals all aspects of detail.

Treble - The highest part of music and voice. See Highs. (Most often used when referring to the treble control on amplifiers).

Upper Midrange (Upper Mids, High Mids) - The audio frequencies between 2 kHz and 6 kHz.

Vivid - A word often used to describe clarity and intensity.

Veiled- Lack of full clarity due to noise or loss of detail from limited transparency.

Warm - Good bass, adequate low frequencies, adequate fundamentals relative to harmonics. Not thin. Also excessive bass or mid bass. Also, pleasantly spacious, with adequate reverberation at low frequencies. Also see Rich, Round. Warm highs means sweet highs.

Weighty - Good low frequency response below about 50 Hz. A sense of substance and underpinning produced by deep, controlled bass. Suggesting an object of great weight or power, like a diesel locomotive.

Width - The apparent lateral spread of a stereo image. If appropriately recorded, a reproduced image should sound no wider or narrower than how it sounded originally.

Woolly - Loose, ill-defined bass.

Last edited:
Entertaining, informative, enjoyable review!
Great review! Has me excited for my Onyx's to arrive. These are my first IEMs after AirPods (lol) so it seems I'm in for a treat
They seem to be a pretty good bet on new IEM happiness! Congratulation on your purchase...........remember that they will change after 60-100 hours burn-in! Welcome to the club!


100+ Head-Fier
Earsonics ONYX IEM Review
Pros: Powerful, Quick & Controlled Bass Response,
Rich Midrange Presentation with decent Level of Clarity and Resolution,
Liquid, Dynamic & Pretty/Silky Smooth Treble Tuning,
Solid Design,
Build like a Tank (Build Quality),
Competitive Pricing
Cons: Not the Richest Accessory Package (Simple Zipper Case, Small Number of Silicone Tips),
Rock Solid Monitor Housing is a bit weighty,
A Balanced Cable or Modular Headphone Plug Design would be Welcome

Earsonics ONYX IEM Review


Earsonics is a famous French company that was founded in 2005 by Franck Lopez and is specialized in the design and production of Custom (CIEM) and Universal (UIEM) In-Ear Monitors and gained a high popularity in the Audiophile community with products such like SM3, S-EM6, SM64, SEM-9, Velvet, Grace, Spark/Blade/Corsa and many more.

The ONYX is a project created by Earsonics with the goal to offer a High-End Universal IEM for an affordable price. It was therefore necessary to reduce distribution and processing costs as much as possible.

The ONYX is a Universal In-Ear Monitor that utilizes 3 BA + 1 DD Hybrid Driver configuration, which is a combination of 2xBA’s desiccated for the Midrange, 1xBA for the Treble area and a custom Dynamic Driver that is responsible for the Low’s. The ONYX comes also with some interesting features such like True Wave, Hybrid and Acrylic Heart Technology, which are integrated in to a fantastic looking Hand Assembled Exclusive Black Metal Shell.



I would like to thank Earsonics for providing the ONYX Universal IEM as review sample. I am not affiliated with Earsonics or any third person beyond this review and all these words reflect my true, unaltered opinions about the product.

Price & Availability:

The ONYX is a special project created by Earsonics to introduce a High-End Universal IEM for an affordable price, which is now available for 490,00 EUR. In order to achieve this price, Earsonics has set up a direct sales website for the ONYX without any intermediary. More information’s can be found under the link below;

Package and Accessories:

The ONYX came in a minimalistic black cardboard box with velvet like surface coating in black color that sports the ONYX branding on the top.


When you open up the top cover you will the Monitors and a zipper case that are carefully placed in to a foam sheet. At the right side of the foam layer is a compartment where you can access the accessories.


Inside the box are the following items;

  • 1 pair x Earsonics ONYX Universal In-Ear Monitors (UIEM)
  • 1 piece x UnHR 4C Silver cable with 0.78mm diameter 2-Pin connectors
  • 2 pairs x Bi-Flange Silicone Ear Tips
  • 2 pairs x Double Flange Silicone Ear Tips
  • 2 pairs x Foam Ear Tips
  • 1 piece x Zipper Case
  • 1 piece x Cleaning Tool
  • 1 piece x Print Material (Warranty Card, User Manual)


The Earsonics ONYX comes with three different types of ear tips. Included are 2 pairs of Bi-Flange Silicone Tips, Double Flange Silicone Tips and 2 pairs of Foam Ear Tips.


The zipper case is pretty small that ports the Earsonics (ES) branding on the top.


Features, Design and Build Quality:

The Earsonics ONYX is a solid looking Universal IEM that shares the same impressive design that we have seen on previous products the Spark, Blade and Corsa.


The ONYX features a Hand Assembled exclusive Mat Black metal shell “100% Made in France” that utilizes 3x Balanced Armature Drivers & 1x Custom Dynamic Driver that are carefully integrated in to the Acrylic Structure, which is the Heart of the ONYX, which is part of the Hybrid Driver Technology.

The heart made of acrylic is supported by a skeleton of the same material allowing it to beat at full speed while avoiding the problems associated with sound reverberation.


The faceplate of the ONYX sports the companies “ES” brand logo and looks wonderful.


At the inner surface of the main body are some artistic notches in form of waves; the slightly angled sound nozzles and a pretty small screw to fix the faceplate to the main body.


The sound nozzle has a smaller diameter compared to other products on the market.


The sound nozzle of the ONYX is equipped with Earsonics “True Wave Technology”, which is a special tube that allows an optimum work on phase control to archive a first-order “Magnitude” curve.


On the top of the monitors are the 0.78mm diameter 2-Pin female connectors that do offer a very tight and secure fit.


At the rear surface of each monitor are the second fixing screws and grid-shaped openings that give the ONYX the look of an expensive sports car, simply eye-catching!


Earsonics UnHR 4C Silver Cable:

The Earsonics ONYX comes with a 2-Pin cable that is made of 4Core high purity Silver Wire cable with a transparent insulation, which has a braided design.


The 0.78mm diameter 2-Pin male connectors do have a metal housing in silver color that do post both left and right markings and color indicators (red for the right connector).


Near the connectors are transparent heat shrink ear guides for a more comfortable over the ear wearing experience, which works pretty well especially on the go.


The cable features a transparent plastic chin slider and a metal Y-Splitter in the same silver color with the Earsonics branding on the top.


The 3.5mm Single Ended headphone jack has an L profiled metal housing with the same silver finish like the rest of the metal part and sports a transparent strain relief for extra durability.


Comfort and Isolation:

The Earsonics ONYX comes with the same Universal Monitor design like the Corsa (the Spark & Blade do share the same design), which all do have a fairly comfortable shape that fits perfectly in to my average sized ear concha’s. The passive noise isolation of the monitors is on an average level that is sufficient for the use in relative noisy environments like a metro, bus or train.


Drivability & Pairing:

The Earsonics ONYX is a very efficiently Universal In-Ear Monitor thanks to is pretty low impedance of 16.5 Ohms and a sensitivity of about 122dB, which makes it fairly ideal for the use with sources like Smartphone’s or Tablets that do have in general relative weak amplification capability.


Technical Specifications:

  • Driver Technology : Hybrid Driver Technology
  • Driver Configuration : 3 BA (2x Mid & 1x Treble) + 1 Dynamic Driver (Bass)
  • Freq. Resp. : 10 Hz – 20 kHz
  • Sensitivity : 122 dB/mW
  • Impedance : 16.5 Ohms
  • Connector : 0.78mm 2-Pin Connector


Equipment’s used for this review:

  • In Ear Monitors : Earsonics ONYX, Oriveti OH500, Dunu DK-4001
  • Sources (DAP/DAC) : HiBy RS6, iBasso DX300, Lotoo PAW S1


Albums & Tracks used for this review:

  • Adele – My Little Love (Spotify)
  • Randy Crawford – On Day I Will Fly Away (Flac 16bit/44.1kHz)
  • Hayley Westenra – Odyssey Album (Dezzer HiFi)
  • Dionne Warwick – Walk On By (Flac 16bit/44.1kHz)
  • Sarah McLachlan – Angel (Flac 24bit/48kHz)
  • Sertap Erener – Aşk (Flac 16bit/44.1kHz)
  • Edith Piaf – Non Je Ne Regrette Rien (Flac 16bit/44.1kHz)
  • Diana Krall – So Wonderful (DSF)
  • Aretha Franklin – I Say A Little Payer (Flac 24bit/96kHz)
  • David Bowie – Heroes (Flac 24bit/192kHz)
  • Elton John – Rocket Man ((Flac 24bit/96kHz)
  • Barry White – Just The Way You Are (Flac 24bit/48kHz)
  • Isaac Hayes – Walk On By (Flac 16bit/44.1kHz)
  • Sting – Englishman in New York – (Flac 24bit/48kHz)
  • Eric Clapton – Wonderful Tonight (Flac 24bit/96kHz)
  • B.B. King – Riding With The King (Tidal Hi-Fi)
  • Dave Gahan – Kingdom (Tidal Hi-Fi)
  • U2 – Sunday Bloody Sunday (Flac 16bit/44.1kHz)
  • Bro Safari, UFO! – Drama (Deezer HiFi)
  • Armin Van Buuren – Vini Vici (Flac 16bit/44.1kHz)
  • Really Slow Motion – Deadwood (Deezer HiFi)
  • Jo Blankenburg – Meraki (Spotify)
  • Lorde – Royal (Flac 24bit/48kHz)
  • Toutant – Rebirth (Deezer HiFi)
  • Gogo Penguin – Raven (Flac 24bit/192kHz)
  • Portishead – It Could Be Sweet (Spotify)
  • Charly Antolini – Duwadjuwandadu (Flac 24bit/192kHz)
  • Michael Jackson – Billie Jean (Flac 24bit/192kHz)
  • Ferit Odman – Look, Stop & Listen (Flac 24bit/192kHz)
  • Chopin – Nocturn No. 20 In C-Sharp Minor (Flac 16bit/44.1kHz)
  • Fazıl Say – Nazım Oratoryosu (Live) (Flac 16bit/44.1kHz)
  • Vivaldi – Le QuarttroStagioni “The Four Season” (Deezer HiFi)
  • Otto Liebert& Luna Negra – The River (Flac 24bit/192kHz)
  • Lunatic Soul – The Passage (Flac 16bit/44.1kHz)
  • Deftones – My Own Summer (Shove it) (Flac 16bit/44.1kHz)
  • Photek – The Hiden Camera (Spotify)
  • Muse – Hysteria (Flac 24bit/48kHz)
  • Metallica – Sad but True (Flac 24bit/96kHz)
  • Opeth – Windowpane (Flac 16bit/44.1kHz)
  • Megadeth – Sweating Bullets (Tidal Hi-Fi)
  • Rush – YYZ (Flac 16bit/44.1kHz)
  • Rush – Leave That Thing Alone (Flac 16bit/44.1kHz)
  • Slayer – Angel of Death (Spotify)s
  • Liquid Tension Experiment 2 – Acid Rain (Spotify)
  • Yosi Horikawa – Bubbles (Spotify)

The Sound:

The ONYX shows Earsonics typical sound character that is mildly warm and lush in its tonality and highly rich and detailed in its presentation. The lower frequency region is punchy, fast and impressively controlled. The midrange on the other hand sounds quite lush, transparent and detailed, while the treble area are shown with a decent level of authority, sparkle and extension, especially for a non-ChiFi IEM at this price level.

The Earsonics ONYX review has been written after a burn-in period of approx. 70 hours. I have used the Stock Single Flange Silicone Ear tips and the UnHR 4C Silver cable that are included to the package.



The lower frequency region (bass) of the ONYX is produce with Earsonics custom Dynamic Driver that is part of the Hybrid Driver Technology. What I have immediately recognized was how well the powerful bass is isolated from the rest of the sounds spectrum, which means that it doesn’t affect the midrange and treble are in a negative manner.

The ONYX offers a solid subbass performance with a powerful, deep and well extending presentation. The ONYX shows a great sense of subbass depth, rumble and intensity when I do listen to string instruments such like the contrabass and bass guitar or with percussion instruments like kick drums, without to have any negative conditions in terms of clarity and resolution. The subbass depth and rumble of the ONYX sounds impressive when I do listen to songs like Massive Attack’s “Angle”, Lorde’s “Royals” and Armin Van Buuren’s “Vini Vici”.

The midbass region of the Earsonics ONYX stands out with its pretty tight, controlled and impactful presentation, which doesn’t show any negative situations such like a midbass hump, muddiness and mixings even in very fast and complex bass passages.

Instruments like cross drums and trumpets are quite accented and do show a warmish and soft tonality. The midbass performance of the ONYX is impressive from rock to pop, from classical music to electronic music. Moreover, I highly enjoyed the bass character of the Earsonics ONYX, which is reproduced in a pretty smooth, rich and full-bodied manner thanks to the well adjusted Dynic Driver.



The Earsonics ONYX shows a mildly warm midrange tonality and offers a very liquid, pretty smooth and lively character, while the sense of transparency and airiness is on an adequate level. The general midrange character can be described a nicely smooth almost velvet like in its presentation but without to sound veiled or dull.

The lower midrange of the Earsonics ONYX shows nice sense of depth, warmth and body when I do listen to vocals like Barry White or Isaac Hayes, which are reproduced in a pretty emotional and full bodied manner, without to show negative conditions such like muddiness. Female vocals on the other hand do sound quite detailed, musical and intimate thanks to the fairly highlighted but highly controlled upper midrange character that offers efficient sense of extension and detail retrieval, while listen to female voices such like Adel, Edith Piaf or Aretha Franklin. The general vocal presentation is pretty upfront and intimate.

The Earsonics ONYX has a mildly warm and highly musical instrument tonality. Everything from guitars to violins, from trumpets to cellos are reproduced in a pretty lush and detailed manner. The ONYX is also a very successful Universal In-Ear Monitor in terms of separation and positioning of instruments and vocals.

For example, guitars do sound slightly warm, a bit bassy and very detailed, while violins do play in a moderately bright and mildly warm tonality, without to show any remarkable harshness and sibilance. Cellos on the other hand are soft, while the contrabass are lightly pronounced and fast.

The general midrange character of the Earsonics ONYX can be described as highly detailed, rich and pretty musical, with both male & female vocals and while listen to instruments from stings to brass instruments.



The Earsonics shows a silky smooth yet pretty detailed treble tuning with a fairly bold and moderately bright treble character, which can be classified as true HiFi like treble presentation.

However, the ONYX offers also enough airiness and sparkle in the treble area to prevent any type of congestions and muddiness while listen to a wide variety of music genres, which makes it to a perfect all-rounder in this area for a wide variety of genres.

The transitions from the upper midrange towards the lower treble region are in general highly controlled in moments when instruments or soprano vocals are reproduced with high level of distortion.

Instruments such as hi-hats, ride or crash cymbals do sound nicely pronounced, while the sense of intensity and extension is on a decent level, which surprisingly good for a Universal IEM with an overall warm (typical Earsonics) tonality.

The treble region extends quite smoothly, especially towards the upper treble region. This area shows a pretty efficient grade of clarity and definition and the fact that the lower treble range is nicely bright and well extending adds the overall presentation a nice sense of dynamism and energy.

All in all, the general treble presentation of the Earsonics ONYX can be described as silky smooth and fatigue-free, while it offers a very easy to listen to treble experience, which makes it also very ideal for longer listening periods.


Soundstage & Imaging:

The Earsonics ONYX shows a pretty holographic soundstage presentation that offers a good sense of separation between the right and the left channels, which makes it to a Universal In-Ear Monitor with a decent performance in terms of imaging. The soundstage shows an above average performance in terms of wideness and airiness, while it has a fairly natural sense of depth.

Some Comparisons:

Earsonics ONYX versus Oriveti OH500:

The Oriveti OH500 features also a Hybrid Driver configuration, which are 4BA + 1DD combinations that are located in an acrylic shell. The Oriveti OH500 has a lightly V shaped sound signature with a nicely done warm tonality and entertaining presentation. The bass is deep, warm and full bodied; the midrange is soft and musical, while the upper midrange and treble region is mildly bright and with good extension.

The subbass depth of both IEM’s is pretty similar, while the Oriveti OH500 shows slightly more intensity and rumble. However, the Earsonics ONYX is superior in terms of subbass authority, clarity and resolution. The midbass region of the OH500 is more highlighted and but a bit muddy compared to the ONYX, which offers a better sense of transparency, control and tightness.

The midrange of both In-Ear Monitors is successful in terms of detail retrieval and do share a warm tonality, while the OH500 shows a slightly warmer character in this area compared to the ONYX. Both IEM’s do offer a full bodied and emotional male vocal presentation, while the ONYX does have a better level of clarity and resolution. Female vocals do sound pretty lively and detailed with both IEM’s, however the ONYX shows a tad better level of clarity and resolution.

The upper midrange and treble region of both the Oriveti OH500 and the Earsonics ONYX is nicely highlighted, crisp and controlled, while the ONYX sounds slightly more natural and detailed. The treble region of the ONYX shows a slightly better sense of extension compared to the OH500.

The soundstage of both the Earsonics ONYX and the Oriveti OH500 is pretty similar in terms of depth and wideness, while the ONYX has a slightly advantage when it comes to the level of airiness and transparency.

Earsonics ONYX versus Dunu DK-4001:

Both In-Ear Monitors do come with a Hybrid Driver configuration. The main difference is that the ONYX is equipped with a 3BA+1DD configuration, while the DK-4001 utilizes a 4BA +1DD driver setup.

The Earsonics ONYX has the upper hand in terms of subbass depth, intensity and extension, while both are successful in terms of control and clarity in this area. When it comes to the midbass area, I can say that the Dunu DK-4001 shows less impact and authority in this area, while the difference in terms of resolution is fairly minimal.

The midrange of the Earsonics ONYX has a more forward oriented, intimate and somewhat denser and warmer tonality, compared to the Dunu DK-4001, which shows a slightly more dry and thin character that sounds a bit unnatural, especially when I do listen to female vocals.

Both the Earsonics ONYX and Dunu DK-4001 do offer a pretty controlled and fatigue-free treble presentation. The lower treble range of ONYX is superior in terms of clarity and definition. It offers also a more natural sense of airiness and sparkle in the upper treble register. The ONYX has in general the upper hand in terms of resolution, brightness and extension in the treble area.

Both In-Ear Monitors are pretty successful in terms of separation a placement of instruments and vocals. The main difference is that the Earsonics ONYX has the slightly edge in terms of soundstage wideness, while the DUNU DK-4001 has the upper hand when it comes to the depth of the stage.



The Earsonics ONYX is a solid Universal IEM, both in terms of construction and overall sound performance. The gorgeous looking Hand Assembled IEM with its Mat Metal Housing, which is 100% Made in France features a very well implemented and coherent sounding Hybrid Driver configuration that is able to produce a very rich, detailed and powerful sound presentation in High-End standards from the top to the bottom. All this features do come for a fairly affordable price, which makes the ONYX to a “Highly Recommended” product below the 500 EUR price range.

Thank you for the Read!
Last edited: