Akoustyx S-6

Akoustyx S-6: An Ergonomic Planar IEM​

Smooth Tuning with Lots of EQ Headroom​

Akoustyx is a small earphone manufacturer based out of sunny San Jose, California. They focus on building neutrally-toned IEMs with industry-leading ergonomics. To date, I’ve reviewed all but one of their IEMs: The S-6. This is Akoustyx’s first planar-driver IEM as well as their first departure from building balanced-armature earphones. How well does this earphone perform relative to its siblings? Does the S-6 stand out from its planar driver peers? Let’s find out!

The S-6 can be bought directly from Akoustyx for $175. It will occasionally go on sale on Drop for around $110.
About My Preferences: This review is a subjective assessment and is therefore tinged by my personal preferences. While I try to mitigate this as much as possible during my review process, I’d be lying if I said my biases are completely erased. So for you, my readers, keep this in mind:

• My ideal sound signature would be one with competent sub-bass, a textured mid-bass, a slightly warm midrange, and an extended treble.
• I have mild treble sensitivity.

Testing equipment and standards can be found here.

The Big Picture​

Pros:

• Aggressive price point
• Friendly tuning — no sharpness, very clear.
• Potent sub-bass, extended treble
• Very easy to EQ
• Outstanding ergonomics w/ EarLock
• Robust accessory package

Cons:

• High levels of cable microphonics
• No more built-in mic

Tech Specs​

• Driver: N50 Neodynium Planar
• Frequency Response: 10–44,000Hz
• Impedance: 18Ω @ 1kHz
• Sensitivity: 108dB
• Cable Connectors: MMCX Gen-2 (Micro Miniature Coaxial) connectors
• Cable Material: Titanium Kevlar mono crystalline OFC (Oxygen Free Copper)
• Cable Length: 1.2M (4.0ft)

Sound Signature​

Sonic Overview:​

The S-6 features a balanced tuning that targets a “north of neutral” sound. It has an extended treble, linear midrange, and precise bass. The S-6’s planar micro-driver is free from artificial timbre or stiffness while maintaining a detailed and poised presentation. The S-6 is largely free from common planar-driver behaviors such as over-sharpened treble or dry bass.

Sonic Breakdown:​

Treble: Songs used: In One Ear, Midnight City, Outlands, Satisfy, Little One, Show Me How To Live (Live at the Quart Festival), Bittersweet Symphony

Treble is often the deciding factor as to whether or not I will recommend a planar IEM. Many that use this driver technology end up over-sharpened or harsh, but not the S-6. While I did need to switch to foam eartips to reduce treble hotness a little, the included Comply eartips are literally perfect. The S-6 went from “barely too hot” to “just right”. I now experience zero treble irritation or sibilant outbursts. I highly recommend that you use Comply eartips for your first listen with the S-6.

As for tonality, the S-6 has a typical fast-responding planar treble. It is resolving, extended, and detail-oriented. It captures treble fade very well and cleanly layers multiple competing upper-register elements like those in the chorus of Bittersweet Symphony. Treble timbre is likewise very competent. String instrumentation comes across with a natural flowiness. The S-6’s extremely fast driver makes it adept at resolving plucky string details, often capturing decay details that even some balanced armature IEMs fail to grasp.

Midrange: Songs used: Flagpole Sitta, Jacked Up, I Am The Highway, Dreams, Too Close, Little Black Submarines, Bohemian Rhapsody, Cash Machine, Chasm

The S-6’s midrange is finely tuned and carefully balanced. It isn’t particularly warm but doesn’t sound thin, tinny, or anemic either. To my ears, the S-6’s mids are natural and free from coloring. A linear lower-midrange frees up a lot of perceived clarity without losing out too much on instrumental and vocal weight.

Texturing and layering is top-notch with the S-6. Granular detail retrieval in the midrange lends itself nicely to picking up gritty textures such as those in distorted electric guitars in Little Black Submarines. Likewise, the S-6 thrives capturing vocal detail — low-fi vocals from the Black Keys, distortion-filtered lyrics from Cash Machine and flowing choirs from Bohemian Rhapsody are all well-represented.

Bass: Songs used: Moth, Gold Dust, In For The Kill (Skream Remix), War Pigs (Celldweller Remix), Cry For Help

Akoustyx sticks to its house-style of tuning giving the S-6 a firm, yet subtle, bass presence. Music won’t rattle your skull (without an EQ), but you’ll get tactile bits and pieces of organic bass production where needed. For example, the S-6 naturally expresses the leftover bass-decay from the electric guitars fading out in Cry For Help ~3:04.

Bass guitars in general are well-bodied. The heavy strumming in Moth is complemented by the S-6’s willingness to bring form to deep-set instrumentation. A part of me did crave a more pronounced bass shelf, but it did not detract from the S-6’s ability to create a cohesive and resolving lower-register.

Electronic music is listenable, though not maximally-fun (without an EQ). You will get a little punch, and slightly more rumble, but won’t experience a visceral recounting of bass drops or synth blasts, such as those in Gold Dust. Less bass-heavy implements like those in the chorus of War Pigs are better suited for the S-6’s “only a little fun” bass tuning as they are more technical and complex (taking advantage of the S-6’s excellent bass texturing and resolution).

Packaging / Unboxing​

Build​

Construction Quality​

The S-6’s external construction is essentially identical to the R-2 series. It has a compact bullet-shaped form-factor. The shell has two main parts between which a colored L/R indicator is housed.



The nozzle-side of the shell is a titanium-oxide-coated aluminum monolith. It is precisely machined and sturdy to the touch. The nozzle itself contains a fine metal mesh that serves as a debris filter.

The cable-side of the housing is built out of a standard poly-carbonate with a smooth finish. It is transparent and permits the partial observation of the electronics within.



Akoustyx continues to use the MMCX cable standard, giving the S-6 wide compatibility with 3rd-party replacement cables. They are using quality-sourced 2nd-gen sockets, but they should be backwards-compatible with any well-made MMCX cable (including the cable sold with other Akoustyx IEMs).



The S-6’s cable is unique to itself and the R-100 (for now). Gone is the finely-crafted exposed-copper cable. It has been replaced with a Kevlar-polymer 3.5mm -> MMCX cable. I have mixed feelings about this change. On the one hand, the new cable has an attractive “understated” look with an improved tolerance to abuse — on the other, I really liked how supple and pretty the previous cable was. In speaking to Akoustyx about the change, they revealed that supply chain issues have made it impossible to continue to build the exposed-copper cables, so eventually all of their models will transition off of it.

The new cable is similar to the old cable in that it has been designed to last a while. It uses high-end connectors and sleeves them in carefully-sculpted plastic shells, each of which features strain-relief sections. This is a standard TRS-terminated 3.5mm cable — it doesn’t have any microphone or built-in controls. What it does have though, is microphonics. The outer layer of Kevlar insulation is springy and hard and transmits a lot of noise when used while walking or exercising. The cable will soften up over time but will not become as soft as the previous Akoustyx cable is.

EQ and Customization​

I don’t normally discuss how well an earphone or headphone responds to EQ’ing as I don’t use them during the course of my assessment — but the S-6 is an exception. When playing around with an EQ before bed I noticed that I could basically make the S-6 sound any way I wanted with zero artifacting or distortion (within reason).
I ended up tentatively settling on the following setup:

• 30Hz + 3.0dB
• 60Hz + 3.0dB
• 125Hz + 2.5dB
• 250Hz + 2.0dB
• 500Hz + 1.7dB

The S-6 gracefully responds to these changes. Its driver seems totally fine with simply producing more bass. I was able to push to +6.0dB and beyond without butchering clarity, but the bass was ultimately too strong for my tastes. You can even get pretty far into “basshead territory” by trading some lower-register texture for sub-bass presence by slamming 30–60Hz up to a (comical) +15dB level and experience PhatFreq levels of bassiness.

The S-6 is not the only IEM that responds well to EQ’ing, but it is one of the most flexible, especially considering how small its driver is. Listeners who want to be able to fine-tune how their IEM sounds shouldn’t sleep on the S-6.

Comfort​

Disclaimer: comfort is a highly individual metric — no two people will have the same experience.

The S-6 is a tiny IEM with a compact bullet form-factor. It will be comfortable for almost anyone. Even my wife, who has very small ears, can listen to the S-6 indefinitely without discomfort.

All Akoustyx IEMs include EarLock ear-guides. They are optional, but a great choice for enhancing fit. If you’re planning on using the S-6 while active, make sure to try out the different EarLock sizes. I found mediums to be a good fit. EarLock does a great job securing the S-6 in my ears to the point that it has recently become my work-out IEM of choice. I’ve used it while biking, skating, rock climbing and running. Never once, even while sweating, did the S-6 slip out of ears. Again, I’d like a cable with less microphonics, but I just switched to using the older Akoustyx cable to resolve the issue.

Accessories​

The S-6’s accessory package is identical to the R-210 and R-220. Inside the box you’ll find:

• 3x pairs of genuine Comply T100 eartips
• 3x pairs of silicone eartips
• 1x pair of dual-flange eartips
• 3x pairs of EarLock earguides
• 1x padded neoprene carrying pouch

The standard Akoustyx accessory package is a good one. A wide variety of eartips, genuine Comply, and a well-sized/protective carrying pouch satisfy any need you might have. No complaints on my end.

Comparisons​

1: Kiwi Ears Canta ($89)
The Canta has a price advantage over the S-6, but that doesn’t make it a clear winner. Firstly, these two IEMs have vastly different goals. The former is a V-shaped hybrid trying to straddle both the dynamic and planar worlds, while the latter is a focused, purpose-built IEM that aims to extract as much performance as possible from a single micro planar driver. That said, listeners who love dynamic-driver bass and want more of it will go with the Canta. No amount of EQ’ing will make the S-6 sound like it has a dynamic driver in it.

However, everyone else who prioritizes parts of their sound signature beyond bass will want to heed the call of the S-6. Its single planar-driver configuration makes it more consistent across different sources and bestows upon it a more cohesive timbre. And its not just timbre — the S-6’s balanced “north of neutral” approach to tuning gives it an analytical edge too. It actually sounds a little warmer than the Canta as a result, owing to its less-recessed midrange.

2: Kiwi Ears Orchestra Lite ($250)
The Orchestra Lite is more expensive than the S-6, but shares similar goals: to produce a highly-resolving, naturally-toned sound. The S-6 is minimalist in its construction while the Orchestra Lite is more grandiose. These differences in physical presentation carry over into their sound signatures.
The Orchestra Lite has a warmer midrange and less-pronounced mid-bass. Its mid-centric nature puts vocals and guitars center-stage while resolving other features of your songs further back in the mix compared to the S-6. The S-6 sounds comparatively less-rich and more analytical, possible owing to psychoacoustic differences between its planar driver and the Orchestra Lite’s 8-BA driver configuration.

Ultimately, the S-6 will appeal more to a purist crowd or planar-driver enthusiasts — which make sense given its studio-reference-style tuning. The Orchestra Lite is double the price of the S-6 though, which might be a big enough price difference to convince you to give the S-6 a chance (the gap is even bigger compared to the usual Drop price) even if you usually go for IEMs tuned like the Orchestra Lite.

3: Rose Technics QT9-MK3 ($159)
The QT-9 MK3 is another hybrid IEM that is rather close in price to the S-6. They’re very different though, with the QT-9 MK3 being much more V-shaped. It, in spite of not having a planar driver, sounds much brighter than the S-6. It has a cooler, more recessed midrange with a weightier mid-bass and sub-bass. The S-6 has a more natural timbre with higher levels of cohesion, particularly in the midrange. The S-6 is also a little better at resolving texture, though the QT-9 has a wider sound stage.

The S-6’s more refined tuning makes it a better choice for critical listening. It is not, however, well-suited to electronic or dance music. If you want lots of juicy bass or an IEM that was designed to be “fun”, then the QT9-MK3’s extra weighty lower register will suite your tastes better.

Summary​

The S-6 is a well-made planar-driver IEM. It is priced well and comes with a great set of accessories. While not everyone wants a subtle and “north of neutral” sound signature, those who prioritize clarity and natural timbre will absolutely love the S-6. While I do wish Akoustyx chose a cable with less microphonics than the new Kevlar one, you can always swap to a different MMCX cable (or even steal an old cable off of an older Akoustyx IEM). At $175, the S-6 is a good deal. At $110, it’s an absolute steal. Great job Akoustyx, I can’t wait to hear your next planar-driver IEM!

As always, happy listening!

California-based Akoustyx Inc kindly sent an S6 sample to deliver a second opinion after Jürgen’s recent article.

It is customary for us in these cases to write a rather succint piece to avoid too much replication of the previous article’s contents but I’m going for an exception here. These little ones do in facts make me feel compelled to share my extended opinions with my few readers. I know, it’ll be boring. Few readers, however, means little damage. So let’s just get down to it.

Just for the record: Akoustyx S6 are currently on deeeep discount sale (like: 50% off) on Drop.

The manufacturer’s official page is instead here.

Test setup​

Apogee Groove / Sony NW-A55 mrWalkman / Questyle QP1R / Questyle M15 / Questyle CMA-400i – Final E tips – Stock cable – lossless 16-24/44.1-192 FLAC and DSD 64/128/256 tracks.

Signature analysis​

Tonality

S6’s timbre is natural, sculpted, muscular and well bodied, and stays so all across the spectrum. There’s above decent microdynamics, and no sign of “artificial” aftertastes. This, alone, would be worth closing my article with a glowing rec.

S6’s tonality indeed deserves some articulated comments. The manufacturer underlines S6 are intended for “studio reference acoustics”. Talking through with them they reported they tuned them closely following the Harman IE2017 target (see below) – and I must say it does show, big time. The presentation I hear from the low mids all the way up is definitely that. Sub-bass elevation is only more modest on S6 compared to the theoretical target.


https://cdn.head-fi.org/a/10122931.png

Simply put IE2017 is not my personal preference, period, and this for two main reasons.

One: the circa 11+dB value gap between the 1Khz and 3Khz points results in highmids being slapped hard into my face when I raise volume beyond a very moderate level, and

Two: the depressed lowmids values convert in a very dry, too dry tonality – I do prefer bright neutral to warm balanced, but IE2017 is below neutral, it’s almost aseptycal.

This has to do with the target itself. Then, depending on the particular driver technology and/or implementation accuracy or lack thereof on this or that driver the “actual” result will be for me moderately bad, very bad, or downight unbearable.

Now, the good news is that planar drivers in general bear tonality corrections by means of equalisation with a certain ease. And, S6’s driver is very flexyble (pretty much in Audeze iSine or RHA CL2 league), so first thing I did of course was bringing tonality more in my preferred ballpark, and a bit off the effing IE2017 “thing”.

Here’s the scoop:



My experience with S6 refers to the first 2 corrections (3K and 4K) imperatively applied. I will outline differences when the optional ones are applied too.


Sub-Bass

S6’s sub-bass is fully extended and quite present. Typical snappy planar transients apply without distortions here so there’s little more to squeeze off the onion so to say. That said those who prefer an even more visceral rumble can experiment with a Low Shelf correction from 50-ish Hz, +3dB (or more) and a very wide badwidth (0.3 or so).


Mid Bass

S6 midbass is seriously good. Oh well, of course it’s good if you like technical acoustic bass as I do. Distorted overbloated bass lovers should never buy S6, period.

Transients are well managed here and while they stay in fast, precision-rendering territory as you expect from a planar, they are not overly snappy and do deliver some body and microdynamics.

Applying the aforementioned warmth correction (Peak 200Hz +2dB wide bandwidth) does exactly what it says: midbass (and not only) will heat up a good 20%, coming across as a bit more bodied and flowery.


Mids

Mids are spectacularly sculpted yet organic and detailed. Guitars and tenor sax benefit most of the situation delivering good nuances and microdynamics while staying precise and seprated (see Separation below).

Highmids is where the IE2017 – and S6 which follow that very closely – loses my personal approval and that’s why in my books S6 strictly require the EQ-based retuning I mentioned above.

Once that’s done however the magic happens in all its splendor: high mids are energetic, detailed, sparkly and controlled (!!), even when you pump the volume up significantly, which is indeed a way to open the presentation up and let S6 give its musical best


Male Vocals

Tenor vocal lovers will be those finding the Wamth correction (see above) most desireable. Without that there’s too much dryness to call delivery really organic.


Female Vocals

Female voices are natural and organic, although not flutey. Good texture available and good microdynamics for a planar.


Highs

On a corrected S6 trebles are integral part of the nice show. Well extended, quite airy, snappy without excesses, not zingy, not tizzy. Love them. Apply the “Extra Air” EQ correction to add further airiness. Don’t be scared nor shy: experiment. Try +3dB, +4dB, +8dB if you want. Only stop where you like the sound best : S6’s driver shall anyhow follow you like a doggie.

Technicalities​

Soundstage

S6 cast a nice sized stage both accross and in depth – a bit more or a bit less depending on fit depth (the deeper the fit, the smaller the room).

Not the absolute widest projection I heard but very good anyway.


Imaging

Macrodynamics are beyond good. Intruments and voices are well scattered on the scene and there is nice air inbetween


Details

This is a point of excellence. S6’s detail retrieval smoothness is easily top rank for my experience on sub-500€ drivers. While I can name other “detail monsters” around, they all will “cost” some or a lot of fatigue and, before that, distraction from the music flow. S6 deliver fine and subtle details without slamming them onto your face nor covering you with “metallic noise dust” as other much leess refined drivers do.

Detail is also good from bass, although to a lesser extent: down there I guess planar-snappy transients do represent an apriori limitation to low frequency microdynamics. Something can be obtained with some light EQing but that’s it. Not “bad” however, just not so outstanding as to point it out as key plus. If you want special bass articulation and nuances get a high end DD.


Instrument separation

S6 execute separation very well. Crowded passages stay perfectly readable at all times, thanks to very controlled transient behaviour, and that glowing compromise mentioned above between snappyness and microdynamics.

Layering is top class: you can follow second or third voices with ease at all times and that’s not trivial to get – at any price, let alone with this small budget.


Driveability

In the “planar drivers” world S6 are probably the easiest to bias I found. You can even drive them from a phone, although you won’t have much headroom to compensate for low recorded materials (e.g. some vinyl digitisations, DSD conversions etc).

That said, their presentation opens up to more details and microdynamics when submitted to somewhat higher power. Once I apply my EQ corrections and the highmids excess goes for good, S6 offer a wonderfully smooth SPL progression. Indeed I find that even “dangerous” insofar as they cease any shouting, and you don’t get any “too high volume warning” so to say when pumping them up. Be careful… we all have only one hearing system you know that, once screwed you can’t fix it…

Like any bright/bright-neutral drivers S6 pair best with relatively warm sources, or at least with non-analythical ones. A special mention for Groove: the pairing with S6 is beyond spectacular.

Finally, a last important point of attention regards the equalisation requirements: your source need to be capable of at least “some” EQing.

Physicals​

Build

The cylindrical part of the housings is in titanium alloy. The supersmooth outside finish is a titanium-oxyde based treatment. The backside is realised of a special polymer, in angled shapen, to properòy house the MMCX connector. Very stylish at least in my tastes, and covered by some patent too.

A red/blue colored ring helps easy identification of the right/left piece. Depending on fitting that ring might end up covered by the Earlock structure (see Fit below), however.

Lat but not least S6 housings are extremely lightweight: once selected the right size/type tips, and worn on with Earlocks etc they virtually “disappear” from your perception. Superb.




Fit

Stock silicon tips are not bad for the job. It’s not so easy to rotate others in as S6 nozzles are quite slim. In the end I settled for Final E (black) as they tend to tame trebles and bring mids forward a bit, which of course helps on re-estabilishing my preferred balance in this particular case.

Technically speaking a good alternative would be Spiraldots too, but their stem diameter is too wide so who wants to adopt them onto the S6 must be ready to apply a tight rubber ring onto the nozzles first, then the tips. Couldn’t be fussed personally, as I found Type-E’s more than good enough.

As you may reacall I am not in general a foamies lover but S6 is one of the few exceptions: here the typical foamies effect (“combing” thinnest treble notes and making bass a whiff “matte”) resolves in a very pleasant timbre nuance alternative.

Once again stock tips are of very good quality – very soft and quickly reactive material, classic cylindrical style – so you can easily go with those to begin with. My effing left canal is always creating problems though so in my particular case S stock tips is too small and M is too thick :-/ My best option is Comply TS200. YMMV needless to say.

Last but certainly not least in importance: the Earlocks. Those are totally brilliant. Think to the IEM version of those “comma shaped” rubber thingies you fit onto earbuds to help the stay put in your concha – and add twice the design accuracy.

These EarLock® silicon “rings” realise several contact points on the outer ear to (literally) lock the housings in place and fit the same way every time. The item comes from a company focusing on hearing protection aids for people involved in very loud noise situations (including law enforcement, army etc) aiming at guaranteeing that the noise attenuator/plug/intercom – whatever stays in-ear – won’t ever budge let alone pull out even in case of sudden hard movements, pullbacks, rush etc etc. And boy do they work!

Simply put: the Earlocks (provided in 3 sizes S-M-L) fit perfectly and “disappear” in/onto the outer ear, I don’t even perceive them as being there once worn, and S6 housings get a 100% firm stability in place, whatever I do however I move etc. This not only means that they won’t entirely slip off, but also and probably even most importantly that they won’t budge even as a consequence of mandibular movements while talking or eating which – in my case it does happen – may produce loss of seal and/or need to reposition.

Long story short: now that I tried them I want something similar for all my IEMs !


Comfort

Subjective differences apart, bullet shapes are normally considered “comfortable”. Amongst their downsides there’s typically stability which is totally fixed by the Earlocks in this case (read above). S6 are not particularly “long” in the bullet shaped category however they do support mid-deep fit, as a free choice user option.

As always: the deeper the fit the softer the trebles, the more relevant the bass, and the narrower the stage. Pick your poison.


Isolation

Using foam tips and Earlocks to guarantee stable fit, S6 reach a whopping 34dB passive ambient noise reduction (NRR 28dB). That’s a lot! We are in professional NR aides territory indeed – these values are indicated for people working on tractors for example, or in some noisy industrial plants. Fantastic. Just be careful walking outside : you won’t hear traffic (!)


Cable

S6 stock cable is an unassuming-looking yet very sophysticated 16 core Oxygen Free Copper conductor. According to the manufacturer it is accuratly impedance-paired with the drivers. Be as it may, it sonically pairs spectacularly well with S6. I tried rotating some others – OFC is definitely the right choice, SP-OFC adds on edgyness which is not required here, Grafene does not pair well either.

As it often happens on low budget packages the cable has a fixed 3.5 termination only (the company is working on a multi-plug alternative to bundle on future versions but that’s on the drawing board yet).

Considering how well the cable pairs with S6 I recommend swapping only to those who are in dire need as all their sources sound best exclusively from their balanced otuputs. In such case a very inexpensive, decent option is the good ol’ ultracheap NiceHCK 16 core High Purity Copper (aka “Ugly Cable”). Alternatively a Linsoul HC08 will do well. Or, wait for Akoustyx to deliver their own,

I guess something more is also worth saying about the cable.

One: the Kevlar sheath may easily be a love/hate thing. The material itself is beyond wonderful, super resistant etc. On the down side it’s badly microphonic (which is probably why the manufcturer strictly recommends over-ear cable install – RTFM…) and it’s quite springy at first. For the latter issue the good news is that the sheath gets obviously softer and malleable after a quite short time.

To quicken such “break-in” period you can frictionate harshly the cable in between your hands after coughly “coiling” it – don’t worry it won’t break – do it a few times and it will already get much better.

Two: the MMCX connectors offer a very firm “click-in-fit”. This may sound like a detail but for my experience it is not (!). Without going too far, this is one of the very few points of structural weakness I underlined on my Miyabi analisis (here). The down side on low quality MMCX options is of course micro-discharges resulting in subtle craclking noise while listening or worse.

Don’t take me wrong here, I’m not saying S6’s stock cable is the one and only good cable out there – I’m just saying don’t discard it quickly replacing it with “just any other one”, as – unlike what too often happens with cables bundled with budget-tier drivers – Akourstyx put a good one in here…

Specifications (declared)​

Comparisons​

7Hz Timeless ($ 199 Drop deal)​

Simply put, S6 are miles better. Timeless have bloated, untextured midbass, a generally artificial timbre, scarce microdynamics (aka invasive “planar timbre”), very modest layering and separation. They also don’t seem to react particularly well to EQing, although some correction do make them a bit better. They do cast a wider stage compared to S6, there’s that. And they are more expensive.

TINHIFI P1 ($ 169)​

P1 offer a smooth, nicely balanced and inoffensive tonality. Possibly a bit “too inoffensive” – one of their limitations for my tastes being that I find them a bit boring. S6 are obviously sparklier, much more engaging energetic and “brilliant” – they do require EQ correction ootb however, which is not an “absolute requirement” for P1 instead. Other major differences are the timbre – P1 being desperately “planar” vs S6’s much better microdynamics – and the driveability – P1 is much harder to bias.

Ikko OH1s ($ 74 promo on Amazon.com)​

Recently price-repositioned by Ikko (I’d like to think: also after our suggestion), OH1S are based on different driver tech (1 DD + 1BA) but offer a general presentation and tonality similar to S6.

OH1S don’t require EQ corrections to deliver good bass, mids, vocals and some technicalities – all coming close to S6, which still has the edge on pretty much all counts, even if sometimes by not much. OH1S fall more evidently short of S6 in terms of imaging, and most of all energy. They are also very much tip dependent, and may not be so easy to fit.

final A3000 (€ 129,99 on Amazon.it)​

By far my sub-300€ clear-timbre, bright-neutral tonality reference. A3000 are built on a custom-developed DD essentially sounding like a planar, and specially tuned prioritising equal clarity on sounds both closer and farther away from the listener position – which is particularly beneficial to acoustic music from large orchestras or groups.

As a direct consequence A3000 win big on sounstage drawing vs S6 – and pretty much any other sub 1K$ driver I heard tbh, solely bar their siblings A4000, which I find however less pleasant for my tastes on other counts (won’t digress here).

Tonal homogeneity, phenomenally nailed compromise on details vs musicality on trebles, layering proweness and well calibrated snappy transients are on par between the two. S6 offer higher note weight and whith that a more energetic, muscular, lively musicality while A3000 are obviously silkier. S6 sound if you wish… american, while A3000 so japanesely discrete-yet-deeply-sophisticated.

A3000 does not “require” EQ out of the box, however its few shortcomings can’t easily be fixed by EQing. Opposite situation on S6, which need to be put hands onto, but can be EQ-pushed/pulled/stirred in so many different sonic flavours, such argubaly being their most solid upper edge.

Considerations & conclusions​

Some 2-3 years ago I auditioned my first planar IEM and I was kinda puzzled. Then I heard another. Then another. And I gave up. Most of all, they were all drowning me into “planar timbre”, i.e. [almost] complete lack of microdynamics. A total turnoff for me. Simply put, I could see no reason why one would prefer one of those to a much more expressive and/or refined fast-transient DD or (quite rare, on low budgets) good BA.

Then in spite of my disappointment for the category last year a friend convinced me to audition a pair of RHA CL2, and that’s where I finally “got” planars: different beasts, indeed. And not at all “inexpressive” as the previous ones I tried.

Too bad that a) those CL2 babies cost a pretty penny, and what’s worse b) they are not in production anymore. “Allright, too bad” – I said to myself. At least now I know “what” I look for “can” exist in a planar, and that I was right on disregarding lower rank / quality alternatives.

Finally, in came Akoustyx.

Simply put, their S6 are truly hightech planar drivers built into a scaled-down, very modestly priced, stellar value package.

I sharply disagree on the apriori choice which as been made in favor of the IE2017 target. In my very modest personal opinion I don’t find it neither studio-neutral/reference, nor pleasantly musical. I was even more disappointed in stock CL2 tuning, however !

The outstanding things with S6 are their spot on native timbre, and their great elasticity vs EQ corrections.

No they do not deliver “precisely the same” technical proweness I heard on RHA CL2. They come seriously close however, with that indeed representing a credible, significant, differently flavored alternative to DD or BA technology budget drivers – that is, at a fraction of CL2’s price.

If you ask me, S6 are indeed worth their full 250$ MSRP, and then some. At their current deal price on Drop they are on “steal” category.

This artcle originally appeared on www.audioreviews.org, here. Our generic standard disclaimer.

General Info/Build/Comfort/Packaging
Akoustyx is an American based company which is based in San Jose, California and their products are all assembled in Nashville, which i personally think it's impressive as they handled everything from design, marketing, manufacturing all within the US itself without outsourcing it. The rationale behind this is to have a better control in terms of QC of the products I believe. Previously there wasn’t much discussion about Akoustyx within the audiophiles community (based on my observation), now the S6 is widely discussed as it is a planar driver, but mainly due to its size.

Build quality of the S6 is good, it consists of Titanium-Oxide coated lightweight aluminium-alloy and polycarbonate, thus making it durable and very light at the same time. It can be worn over the ear or straight down, personally i prefer it to be over the ear as it minimises the microphonic that the cable produced, the supplied ear fin keeps the S6 firmly on your ear, i have tried to move my head vigorously but the S6 remained in place in my ears, fit wise, it really is very good. No complaints about it.

Packaging is rather minimal and straight forward, it came with a sturdy storage case, various sizes of ear fins and ear tips, a high quality Titanium Kevlar mono crystalline OFC cable.

Gears used for this review

• Akoustyx S6 with stock cable and stock eartips with M sized Ear Fin
• Topping DX1 + Topping NX7
• Earmen Angel Dac Amp
• Sony Walkman ZX300 with MrWalkman’s Firmware
• iPod Touch 5th Gen
• Macbook Air M2’s 3.5mm port

Sound Impression
The S6's sound profile is more V shaped to my ears and there aren't any peaks or gains as far as my ears can tell. The tonality is slightly bright with sufficient texture so that it doesn’t sound thin. This set is not for basshead in my opinion and those whose preferred target is the harman curve. Technicalities of S6 are no slouch and the timbre is rather natural for a Planar, there is a slight tinge of planar timbre if you try really hard to look for it, else it is discernible. Let’s take a look at the breakdown below:

Bass

• As many would have expected from a Planar driver, the bass is speedy and good control, and it is impressive especially if you consider the size of the planar driver
• If you’re expecting S6 to rumble like there’s no tomorrow, you may wanna look at some other options. Sub bass rumble is there when the track calls for it, but nowhere near basshead level kind of rumble
• Mid bass is punchy and has enough speed to handle tracks like Metallica’s Lux Aerterna, Slipknot’s People = crap!
• Doesn’t bleed into the mids for sure

Mids

• Mid range is slightly recessed as expected from a v shaped tuning, but not overly recessed to the point where it’s bad
• Vocal is slightly recessed but textures are good
• Male vocal is a little lacking in terms of texture, however, female vocal sounds sweet and lively
• Pinna gain/upper mids is rather standard and nowhere near shouty, it also contributes to female vocal giving it a little extra energy and vividness to my ears

Treble

• Treble is energetic but not offensive, it also has a good amount of details
• Good amount of air and busy track doesn’t sound congested at all
• Nothing much to write home about the treble as it is nicely done and never once i felt that it was sibilant
• Detail retrieval is good for the asking price

Soundstage/Imaging

• Soundstage is average, not too wide nor sounds big, good enough and it gets the job done. Average width, height and depth
• Imaging is good with the amount of air, the track doesn’t sound congested and instruments can be pinpointed easily, layering can be better though, just nitpicking

Driveability

• S6 is very easy to drive, it will get reasonably loud even with an Apple Dongle or straight out of 3.5mm from your phone
• However, it does scale with better source as well as more power
• Due to its slight emphasis on the high region, i personally find it to synergise well with slight warm source and also copper cable

Comparison (Dunu Talos - Planar only mode)

• Build quality of both are good and fit wise, S6 definitely pulls itself ahead
• In terms of sound profile, Talos is more on laidback listening, rather neutral, which S6 is more on fun sounding and slightly energetic listening experience
• In terms of technicalities, both are more or less on par, more than that its just nitpicking and self preference in my opinion

Final Thoughts
S6 is a very good IEM in my opinion and it definitely deserves some attention from the audiophile community, with the invasion of Chi-Fi planars, it is good to see an American branded planar driver IEM at an attractive price which has good sound and also good technicalities. The S6 has gained its traction within the audiophile community and it can be seen being discussed among various groups on Facebook. I can’t wait to see what Akoustyx has in store for the next release. I will not hesitate to recommend the S6 to anyone who’s looking for a set of fun sounding IEM.



*S6 is sent to me from Akoustyx in exchange for this review. I thank them for the opportunity given.

If you’re interested in getting a pair, head over to Akoustyx’s store to get a pair now, at the time of writing, it is currently on a sale price of 175$
Akoustyx S6 - Non Affiliated Link

TONALITY: 7.2/10
TECHNICALITIES: 8/10
CONSTRUCTION: 8.2/10
SOUND VALUE: 7.2/10

INTRO


AKOUSTYX is an American start-up manufacturer based in San Jose, California with their assembly line in Nashville, Tennessee NOT in China….which is something I truly admire nowadays where even big brands do not tend to care to assemble their product in their own country mostly to higher their benefit, not to lower the price of their final products. This fact tends to make the final product less rushed in production, which at the end can result in more trustable craftsmanship and quality check.

Behind their company, they have a team of musicians and audiophiles, which serve them to achieve acoustic qualities that will please as much musician searching for reference monitor sound than audiophile searching for musical reference sound.

Today I will review their latest release, the S6, which is an ultra small planar IEM using a 6.2mm double sided magnet planar driver patented by Akoustyx themself.

Priced 175$, the S6 promise a ''studio reference tuning'' that put emphasis on clarity.

Let see if this planar IEM can stand out of ver competitive sub-200$ market in this review.

CONSTRUCTION & PACKAGING

UNBOXING experience is a very rewarding one. The presentation is minimalist, but you are spoil by lot of accessories in the box. I’m often underwhelmed by the protective case included with earphones, not this time because we have a superb neoprene padded carrying case that has 2 pouch with a zip so you can bring an extra cable with the R-220. It’s really a well-crafted carrying case that I will use daily.

As well, you have good amount of ear tips including their own-designed customization kit ear tips, silicone ear tips and a pair of memory foams ear tips. The cable include is titannium kevlar coated OFC and feel very sturdy. Quality is OK, but ear hook choice is questionnable.

CONSTRUCTION is simple yet well made. S6 use the exact same IEM housing than the R-210-220 with black color instead of blue. It’s supremely small, and a unique look that looks like a mix of Etymotic and Final Audio F iem. Material of housing is a mix of aluminum alloy and polycarbonate plastic. Sturdy and classy looking iem that promises long durability.


DESIGN is nice and comfy, it’s so small that it will fit any size of ears. As well, you can both wear it over-ear or cable down. It must be noted that if you wear it cable down, cable will create microphonic. As well, with ear hook, over-ear design is less comfortable than with a soft flexible cable without ear hook. But, and this is an important BUT, if you use the earlock tips, the ear hook problem is partly solved as the fit will be very secure. Earlocks tips cancel any unwanted movement, but I don’t think it is very comfortable. In fact, I prefer using another cable and wear the R-220 cable down.

ISOLATION is impressive and it really acts like noise ears plug when used with memory foam tips. As well, sound leakage is inexistant, which is a big plus.

SOUND IMPRESSIONS
Listening to the S6 was a real roller coaster ride, let say it sure doesn't let you indifferent for the better and the worst. These are bright energic V shape where the bass is all about fast bright punch and upper mids and treble is most boosted part, so, you can feel these are neutral when their no bass then when it hit, it hit hard and overall very foward and immediate musicality hit you like a wall.

I can't listen to those at high volume, and Akoustyx underline to me that the ultra small 6.2mm planar driver is sensitive to loudness and will indeed create harmonic distortion at too high volume. So, are these the kind of IEM that are overboosted in clarity so we can perceive high resolution at low volume? I do think so and I do think it's a very risky approach to tuning too, since pinna gain is intensely boosted here and do create upper mids issue that can't be overseen even at lowest volume.

And depending of your psychacoustic awereness, resolution will perhaps feel scooped in sound info, overly colored, confirming again this isn't neutral IEM at all but unapogically intense and sharp sounding. Sure not boring, the Akoustyx are planar on amphetamine, impatient to rock your sock off.

The result can be highly engaging for simple rock or folk track or dangerously over excited when it come to busy jazz fusion or classical symphony track.

The bass is all about urgent loud punch and boosted presence texture, depending of bass line and kick drum instrument, it can go from wow to What. With a track like ',Magic Arrow'' from Timber Timbre, we are in wow territory since the kick isn't hitting hard in the track, it's well texture and define with good weight and the electric bass line is superbly articulated but doesn't dig low, wich benefit S6 limitation. So, this is the type of bass that doesnt lack bite, not weight, but is limited in linear rumble so for big beat with heavy boom it can go into What territory. Why? Because bass is overly boosted for a planar and when bass is loud in a track, it will be multiply in boomy way with euphonic sustain that affect proper roundness. This can be distractive and tend to make mid range even more recessed, some veil and bleed can happen, stoling instrument separation air. We are in quantity affect quality here, and we have a sub bass roll off too that is replace by boom resonance that darken low end when it occur. But again, I underline that bass line can be fastly redered in presence and definition when they have texture and the attack speed can be mind blowing with an album like ''Not tight'' from Domi & JD beck, where the drum is fast and punchy, well define and have good layering with the bass line that is more about high pitch play. Things begin to go wrong with heavy trap track like ''Broken Clocks'' from SZA which is all about unclean foggy big sub boom and overly sharp percussion, with lost in dark female vocal. Bipolar low end that lack versatility, elasticity and flexibility.



Mid range is most recessed part of the spectrum and can get crumpled between bass and treble quite intensely. Let say these Akoustyx aren't for piano lover, an instrument that blossom in mid range, here it's barely hearable sometime, for ex, in chamber orchestra violin will overshadow with their bright presence the warm and dark piano note that lack definitio and attack edge and feel 1km more distant than other high pitch instrument. Even with calm jazz track like ''Air'' from Dieter Ilg ''B-A-C-H'' album, the piano seem more distant than both bass and percussion, bass is all about texture bite, not very bodied and extended while percussions is super sharp, strangely, piano sound clean and well resolve but lack note weight and loudness amplitude, so this confirm that busier is the track, darker is the mid range. Then upper mid range came to the rescue and brighten what it can, which is mostly texture and presence of mids instrument, we have extra lower mids meat too that will favor some male vocal or female vocal, but the mix of low harmonic and boosted texture presence can lead to very wonky vocal too, as well as problematic sibilance and shoutyness. Yes, the Akoustyx are wild and imprevisible and certainly not for mids, tone, timbre and vocal lover in general. For natural timbre, better go with Tangzu Zetian Wu.

Treble head rejoice! Your in for a treat with the treble centric S6, but it's not for fainth of hearth even if it's not spikiest treble have ever heard from lower to upper treble. Before 10khz everything is boosted, energic, bright in texture and sharp in edge. While this is problematic for some vocal and can make violin sound amplify by an electric guitar amp, it can be rewarding for solo drum percussions due to lighting fast attack speed. Yes, this micro planar driver sure is in a rush to impress us with it's fierce transient speed and wow effect can occur for non sensitive listener. This is abrasive treble that favor presence and texture saturation, it have crunchy attack with short bright sustain, it's not the cleanest nor snappiest treble, and it lack sparkle and air as well as brilliance and and surely full extension up to 20khz. Yet, the abrasive texture add a sens of urgency to the music by puting fowards percussions and micro details part, it add extra dimension to an overall compressed spatiality. Snare can sometime be hot and hit quite hard, but even if a hint raspy by time, the percussions timing is vividly presented and hook our attention, sometime in mind blowing way when mid range instruments aren't the focus of music. But don't expect end game refinement here, as well as full clear extension, clavichord and harp sound dry and scooped in resonance amplitude with the Akoustyx, this mean acoustic guitar too lack sparkle and natural decay.

Their not alot to say about the soundstage, apart that it's average since whole sound presentation is rather fowards and in your face. So, it's an intimate listen, and it do feel stock in your head since widenes and tallness is lacking as well as overall sens of openess. We have some deepness, but it's limited too.

Yet, the imaging is surprisingly decent within this space limit, this is surely due to fast transient speed that permit sound layer to be extracted from each other. So, while their not alot of space between instrument in X axis, fast separation in Y axis permit precise positioning enough.


COMPARISONS



VS TANGZU ZETIAN WU (1x 14.2mm planar-140$)

First thing that hit me is how more open and wide is spatiality, deeper too, more holographic with wider instrument and mids instruments presence. As well, the Wu is notably warmer, smoother and better balanced, it sound more musical and laid back than more fowards sounding bright and agressive S6. Then the vocal, both male and female are fuller, lusher more wide open and natural in timbre, overall mids are less recessed, better rounded and less thin bright than S6. Bass is chunkier too, more rumbly and well define in body, its less textured tough, and the punch is slower, thicker and warmer in separation. Then the treble, well, let say S6 have both lower and mid treble notably more boosted and less cohesively and organically balanced than the WU, it's sharper and edgier in definition too, percussions being more fowards with the S6. S6 treble si faster in attack, less blurry in edge, snappier and more detailed and even more brilliant and airy than the WU, which is dark on top, have less thin highs but poorer overall resolution even if the macro presentation is more realist and richer in sounds layers density. Spatiality is wider and taller with the WU, a bit deeper, tunnel like way, with S6. For imaging, the S6 is superior even if more compressed in presentation, while instrument have more space between them with the WU, this space isn't clean a make sirupy the layering as well, while S6 isn't most realist in positioning, since the percussions can feel on front stage for ex and center instrument from mid range will be recessed irrealisticaly, the separation is sharper and cleaner and permit better static instrument pin point than the WU.

All in all, the S6 is more agressive and technical sounding, less well balanced and more artificial sounding than the tonaly superior Zetian Wu.

VS TINHIFI PANDA (1x Planar-120$)

Simply put the Panda is a better balanced and less excited V shape S6. While bright, it's smoother and not as boosted in upper mids. The bass is less boosted but have punchy well textured mid bass punch still, sub bass is a bit thicker and fuller extended with the Panda too. Mids are thicker, smoother and more natural, not as boosted in texture too. Treble is bit dryer, smoother, fuller, less fast and snappy, bit more blurry in definition edge. Spatiality is again more wide open and now deeper too, more holographic. Imaging is on par or superior due to more transparent layering.

All in all, Panda is both technicaly and tonaly better than S6.

CONCLUSION

The Akoustyx S6 are surprising planar IEM that deliver an energic and engaging bright and punchy musicality.
It merit an applause for being the smallest planar IEM on the market.
In term of sound value, it enter a very competitive market since chifi have release tremendous amount of good planar earphones in 2022 and the Akoustyx came late in the game with a sound quality that lack a bit of refinement and tonal balance versatility.
While not plain bad, the S6 is still an agressive sounding IEM that will not be appropriate for treble sensitive listener as well as those that seek natural timbre and full tonality.
I think this IEM is aimed for those searching ultra small and portable earphones that deliver impressively detailed sound at low volume, and for this purpose, it's valuable.

Half-recommended!

Firstly I would like to thank Akoustyx for sending this S-6 sample for review.

*disclaimer: This sample was provided for the purpose of writing a review, no incentive was given to write a favourable review. All opinions expressed are my own subjective findings

Gear Used:
iBasso DX200 > S6
JDS Labs Atom DAC+ > Singxer SA-1 > S6



Specs:
• Type • In-Ear Universal Fit
• Transducer • Planar Magnet
• Magnets • Neodymium N50 (Front & Rear)
• Frequency Response • 10 – 44,000Hz
• Impedance • 18Ω @ 1kHz
• Sensitivity • 108dB
• Connectors • MMCX Gen-2 (Micro Miniature Coaxial) connectors
• Cable • Titanium Kevlar mono crystalline OFC (Oxygen Free Copper)
• Length • 1.2M (4.0ft)

https://akoustyx.com/products/s6

Packaging, Build Quality and Accessories

The Akoustyx S-6 come in a small black rectangular box, with a render of the IEM’s on the front and a list of features along with specs listed on the back. It’s a simple outer packaging, inside this you’ll find a sturdy inner box that holds the IEM’s securely in place via a foam insert. Underneath the insert you’ll find the accessories, the packaging may not be lavish but it serves the purpose of showing what the item is along with keeping them secure during shipping.

The build quality is good overall, the housings are made from a sturdy titanium-oxide coated alloy and have polymer moulding where the MMCX connector sits. The MMCX connector is tight and I can’t see any issues in the long run here. The cable isn’t hugely thick, but it is a little stiff (probably due to the titanium Kevlar shielding). Overall I can’t comment on how long these will last, but they have held up to daily use for a few weeks and still look brand new, they do feel well put together.

The S-6 come with a good array of eartips, you get S, M and L along with bi-flange tips in silicone, along with S, M and L foam tips. You get a selection of Surefire earlock wings, I personally don’t use these as they fit well without but I can see these being beneficial for a more secure fit for some. Last but not least you get the signature Akoustyx neoprene carry case, I really like this case as it is small, compact and lightweight whilst also providing a good level of protection for the earphones. A good selection of accessories is included with the S-6.



Comfort, Fit and Isolation

The Akoustyx S-6 are small and lightweight, with a barrel shaped body, it’s easy to achieve and comfortable fit with this style of earphone and I never found any comfort issues. The one thing truly holding them back is the cable, it’s a little too stiff and doesn’t like to stay where you want it to. Due to this, there is also quite a lot of cable noise if you wear them straight down, I found myself having to wear them with the cable routed over the top of my ear to fix this. It is an easy fix, but still slightly annoying.

These can be fit shallow or deep, due to the housing shape, so it’s down to you on how far you insert them. They fit well and don’t fall out, you can also try some of the Surefire wings to get an even more secure fit if you need it, but just with normal tips I didn’t find any fit issues.

Isolation is really good on the S-6, perfect for noisy commutes and daily use they effectively block out quite an impressive amount of outside noise. No complaints on the isolation front, just the cable noise when wearing them straight down.



Sound
Lows: The Akoustyx S-6 use a planar magnetic driver, but unlike most full-size planar headphones, the bass response isn’t linear to 1kHZ – instead you get a mild sub-bass lift on the S-6 that gives the sound some body. There is good punch and dynamics whilst digging deep into the sub-bass without suffering from sharp roll-off. Kick drums are punchy, with great body backing up the initial kick giving them a realistic tonality.
The S-6 seem to handle well recorded music best, I know this should go without saying, but they do seem to be a little harsh when it comes to less-than-ideal recordings. I feel this is to do with the upper-midrange peak masking some of the fullness of the sound. The transition into the midrange is handled very well, there is no loss of detail, or added fullness to the lower midrange.

Midrange: The lower midrange sounds excellent, there is good tone to lower male vocals, and guitars have impressive levels of detail. Each instrument occupies its own space but with good cohesion, subtle intricacies in tracks are easy to pick out and on a technical note the midrange sounds very impressive.
However it is in the upper midrange where the S-6 begin to suffer a little, they have a peak that can introduce a little fatigue during certain tracks. The fullness of the bass is counteracted by a forward upper midrange that causes certain vocals and guitars to sound a little thin in tonality and this can throw off the overall balance a bit.

Highs: The treble region is very good on the Akoustyx S-6, it is airy and crisp without being upfront and in your face. There is great extension with soft roll off towards the top so you don’t miss out on any of the finer details. The top end is very refined and smooth, yet packs an impressive amount of detail, all with a good level of presence. If anything they are ever so slightly pushed back in the mix, which does accentuate the upper midrange peak, however this does mean that the treble isn’t fatiguing.

Soundstaging and Instrument Separation

The soundstage on the S-6 is fairly wide with some out of head experiences to be had, there is also good height so it’s easy to place instruments within a space.
Instrument separation is good on most tracks, the upper midrange peak can however cause some congestion when the mix becomes more complex (most noticeable on heavier tracks).



Conclusion
My experiences with Akoustyx have been mixed, but I do think they have a good team behind them that know how to tune a good earphone. The S-6 is an interesting model, due to the fact that there are not a lot of planar earphones out there currently.

However, these still are not what I would call perfect, on some tracks the S-6 sound excellent with realistic bass kicks that have great body and articulation, a detailed and open midrange and slightly soft but well extended treble. But then the wrong track shows up and highlights the shortcomings of the S-6, mainly an overpowering upper midrange that can make the sound quite fatiguing.

These are not as good an all-rounder as the KiiBOOM Evoke I recently reviewed, and as such I cannot highly recommend them in the same way, but I will commend Akoustyx on the S-6. This is not an earphone that is easy to build or tune (small form factor planar magnetic), but they have done a mostly great job and technically there are areas where they excel.

Sound Perfection Rating: 6/10 (A commendable effort, with certain aspects being excellent, but others that create some fatigue)