Ikko OH1S

Ikko OH1S are by the same makers of OH10 – one of the just two $200-IEMs stuck onto our Wall of Excellence, and my personal absolute preferred V-shaped IEM south of 3 times its price.

This OH1S model is presented as an evolution of its previous siblings in terms of technology, and carrying a quite different intended tuning compared to OH10. Formally positioned at $199,00 list price, same as OH10, it benefits of an introductory price of $139,00 (more on this later) which makes it very appealing for a quick grab. And you can bet it’s currently being hyped around. Which is more then enough to move my critical curiosity and spend quite some time with it to see if I agree with the hype (which, you know, is quite seldom the case) .

Test setup​

Sources: Apogee Groove + Burson FUN + IEMatch / Apogee Groove + iBasso T3 / Sony NW-A55 mrWalkman – JVC SpiralDot and Ikko i-Planet foam tips – Linsoul LSC08 cable – lossless 16-24/44.1-192 FLAC tracks.

Signature analysis​

Tonality General tonality is bright-neutral, timbre is dry-centric. The presentation is a mild reversed-L with rulerflat midbass, mids taking the lead role but without getting too “important”, supported but very nice, airy and quite detailed trebles. Coherence between the DD and BA drivers’ different nature is properly taken care of and the entire presentation is choesive and well merged.

Sub-Bass Sub bass is evidently tamed although not completely rolled off. Rumble is present, not strong enough to impose its presence when the musical passage is crowded though.

Mid Bass Fast, moderately punchy and very clean. Purposefully kept not loud, although much less so than the sub bass, OH1S midbass offers a very pleasant compromise for acoustic music genres.

Mids Thanks to the bass’ flat nature, mids come accross quite easily, although I wouldn’t call them “forward”. Also, their timbre is somewhat dry – which I tend at this point to consider a sort of Ikko “house soundprint” – and I happen to like how well calibrated that is in this situation by the way. Frequencies from 2 to 4 KHz are definitely forward which makes guitars and other instruments, together with female vocals take the show lead easily and with very good authority

Male Vocals I quite like OH1S male vocals although just a tad less than females. Their tone is right, timbre on the dry side, but weight is there and tenors and folk singers get the right amount of justice

Female Vocals Female vocals are definitely well rendered on the OH1S. On the dry side timbre-wise but well bodied and articulated. Wring tips or fit may scant into sibilance or excessive thinness so be warned.

Highs Once properly fitted, OH1S’ 8KHz peak is far from delivering negative results as one may be scared of upon seeing it on its graph. Trebles are well extended, vivid, airy, quite but not overly dry (similarly to the rest of the presentation), and again, once the right housing fit is achieved no shouts nor screeches will come out. Well done.

Technicalities​

Soundstage OH1S casts a stage with average width and depth, and very flat in terms of height. The spatial sensation is improved by the airyness granted by the well tuned trebles.

Imaging It’s quite good in general but occasionally degrades on some tracks, mainly in conjunction with high-mid and treble crowded passages.

Details Many, well distinct and pleasant – both on the highmids and trebles and on the bass. Definitely amongst the best parts of the product.

Instrument separation Separation and layering, unlike imaging, are consistently well carried out pretty much in all occasions

Driveability OH1S are relatively easy to drive in terms of power, with some caveats in terms of quality: avoid bright and/or lean note weight sources.

​

Physicals​

Build Housings are made of two parts, one in resin the other in “aviation grade” metal alloy. According to Ikko this allows for lower eight and better frequency separation between the two drivers installed inside. What’s sure to anyone handling them is their convincing solidity, small size, and light weight. Wether the good sound results depend, or to what extent do they depend on the internal cavity – I admit – I am unable to assess.

Fit OH1S does greatly benefit of finetuning fit / positioning into the ear canal to produce optimal sound results. My recommendation is either wide nozzle silcon tips (e.g. JVC Spiraldots) with drivers pushed in as much as possible, or Ikko’s i-Planet stock foam tips. Both options produce better “combed” trebles without any detail loss; foamies also add further bass volume, again without any detail loss, and much better passive isolation.

Comfort Again, due to their “spot on” physicals, I find OH1S very comfortable, even after realising the best sound results are obtained by pushing them as deep as possible into my ears.

Isolation Passive isolation is quite sub-average when adopting silicon tips, as the housings are not “filling” my concha. Situation improves dramatically by adopting Ikko’s i-Planet foamies.

Cable OH1S comes with a good quality high-purity single crystal copper silver plated magnetic core cable. Sound-wise that’s not ideal: it tends to add further brilliance to the trebles which is the opposite of what want in this case. I got best results with a Linsoul LSC08 (2*44core 6N OCC single-crystal copper) cable, or alternatively with a less expensive NiceHCK 16 core High Purity Copper one.

Specifications (declared)​

Housing Resin + aviation grade metal alloy mix, with special designed internal cavity to optimise sound volume, reflection and diffusion angles.
Driver(s) 1 10mm deposited carbon nano dynamic coil driver + 1 Knowles 33518 Hybrid BA unit
Connector MMCX
Cable 127μm high-purity single crysstal copper silver-plated cable, single ended termination
Sensitivity 109 dB
Impedance 32 Ω
Frequency Range 20 – 40000 Hz
Accessories & package Leather pouch, 2 sets of 3 size (S, M, L) bell-shaped oval silicon tips, 1 set of 3 size (S, M, L) i-Planet foam tips, 1 Ikko brand pin, 1 MMCX removal tool, 1 pair of spare nozzle filters
MSRP at this post time $199,00 ($143,00 current special deal)

Some important notes and caveats​

Burn in​

For my personal experience, burn-in is way more rarely required than what I read around on a daily basis. That said, this is one of those times when it is compulsory. When I first put OH1S into my ears I appreciated them nowhere near how I appreciated them after a) a couple of days of free burn-in and b) optimising the fit aspect (see below).

So if you do get them, let them play a bit on their own.

Fit​

Fit is probably “the” critical point with OH1S.

Not in the sense of difficulty. Wearing them is not problematic nor uncomfortable at all per se – the other way around, actually! – but it just takes a brief audition to realise sound, with particular regards to highmids and presence trebles, do change depending on how you position the housings into your external ear.

Given a bit of acquired experience with other equivalently capricious IEMs it took me relatively short to realise I better adopted a pair of shortstemmed, wide nozzle tips (e.g. JVC Spiraldots) and manage to push the drivers as much as possible into my canal: with that done, trebles get “combed”, less hot, the presentation gets less aggressive, definitely more elegant indeed. Thanks to OH1S design the housings are small enough that gently pushing them towards the inside of the concha does not result in an uncomfortable fit. At least for my ears!…

A solid alternative to obtain a very pleasant sound result, however, is using Ikko’s i-Planet foam tips, those bundled inside the box.

I am not a foam lover at all, and that’s possibly the reason why I was so surprised on how well these foams apply to these drivers: trebles are “combed” like it happens with short-stem silicons and deep push, bass gets a bit less edgy, but both extremes do not lose detail in the process. Furthermore, i-Planet foams significantly improve in passive isolation !

Cable​

OH1S comes bundle with a very nice-quality “high-purity single crystal copper silver plated magnetic core” cable. Yeah almost a tongue twister I know, still, a good cable product, really. Build quality and sound transmission are very good, and way above what in the average you can find bundled with IEMs on this price range.

…Too bad that it does not pair ideally with OH1S.

The stock cable is what I would call a “bright” cable, i.e. a cable facilitating high mids and treble crystalline notes – which is the opposite I would personally choose as a good pair for the OH1S.

As a matter of fact, pairing OH1S with a (equivalently high quality) full-copper cable helps adding a bit of note weight and furtherly helps “combing” treble thinner peaks a little bit. I’m using a Linsoul LSC08 (2*44core 6N OCC single-crystal copper), which is by the way the same I’ve adopted on the OH10 – of course a different sample, with 2p connectors in that case. A less expensive but still very good alternative is the NiceHCK 16 core High Purity Copper cable.

One key comparison : Final A3000​

Final A3000 ($130) is the single IEM that we deemed deserving to be stuck onto our Wall of Excellence in the $80-$200 bracket, and – to my experience – the champ of bright-neutral tonality drivers up until switching over to Oxygen, for twice its price tag. So I find it quite natural to bench the OH1S vs the A3000 and see hear how they fare.

Sub-bass is much more present on A3000, not tamed let alone rolled off. Mid-bass is also definitely more elevated on A3000, while keeping equivalent speed and definition compared to OH1S.

Mid tones and especially highmids are significantly more recessed on A3000, which brings them to appear “behind” the midbass – exactly the opposite of what happens on OH1S. Mid frequencies with particular regards to vocals have a leaner note weight on A3000 but the overall timbre is less dry on A3000 nonetheless, and the tonality is warmer in comparison to OH1S.

Trebles are a tad airier on OH1S but note definition is more organic on A3000, whereby OH1S sometimes comes accoss a bit thin on some details.

On soundstage and imaging there’s no game: A3000 is holographic and extremely precise. Layering and separation are I would say on par though.

A3000 are way more capricious to bias due to their much lower sensitivity, and higher altogether amping quality demand. On the other hand A3000 are way less tip / fit dependent – they deliver their best result with much lesser effort on that front.

Conclusions​

At the bottomline I would say that OH1S – at its initial introductory smart price of $139,00 – is 100% a fair contender onto the $100-$150 market bracket. I would surely recommend OH1S for vocal tracks, for example. And in general to get a different flavour of a very well tuned, coherent, affordable driver for jazz and other acoustic / unplugged musical genres.

On the flip side I do humbly suggest Ikko to convert its current discounted price into the regular list price. Raising it to $199 or thereabouts would in fact bring OH1S into direct or close to direct competition with higher tier alternatives, and that I’m afraid would be a pity.

This sample of Ikko OH1S has been provided by the manufacturer free of charge for this review.

You can buy them if you like from their own website, at this link.

Disclaimer​

I am not, nor Audioreviews is, commercially affiliated with Ikko, and I/we are not getting commission for any sales happening from the link above.

This article previously appeared on Audioreviews, and on my own personal website.

IKKO OH1S ($199): DOES THE ‘S’ STAND FOR SUPER?​

My apologies, it looks as if my review was removed…so I am posting it again.


Ikko: Does the ‘S’ stand for Super?
Pros:
Solid Ikko build
Solid Ikko sound
Good bass
Good vocals
Good looking

Cons:
Case
Oblong nozzle (to me)
Fit of tips (make SURE they are connected…)
Tough price point? See below comparisons

Ikko OH1S ($199): Does the ‘S’ stand for Super?

Ikko OH1S

Intro: Ikko contacted me after finding my OH-1 review. Through conversation, a review unit was to be send my way. Rebecca stated that I would probably like the updated version based upon my previous liking of the OH1. I have no financial obligation in the OH1S, nor should it be sold for profit (still uncool). It is understood that the unit may be asked back for at any time. Until then, the unit is mine to keep and use. I added many comparisons below, since the price point seems to be the hot bed at the moment.

Rebecca asked that the unit be burned in for a minimum of 50 hours. The new carbon nano driver needed that time to fully break in. You can make of that what you want, but I have always felt the user appreciates what the unit sounds like six months to a year down the road, not directly out of the box. Hence, I burn in all units, regardless.


Specs:

1DD+1BA Hybrid Driver—32Ω 10mm Deposited Carbon Nano Dynamic Coil + Knowles 33518-unit hybrid driver makes the three-frequency balanced, the in-ear headphones use resin and aviation-grade aluminum alloy as the sound cavity to achieve the physical frequency division effect.


In The Box:

• OH1S-2 driver unit
• Detachable MMCX Cable—-OH1S upgrade cable is composed of 127um high-purity single crystal copper silver-plated magnetic core
• 6 sizes of silicone eartips
• 3 sizes of sponge (I-planet)
• storage box
• LOGO brooch
• Instruction manual

Gear Used/Compared:

CFA Honeydew ($249)
CFA Satsuma ($199)
Thieaudio Legacy 4 ($195)
BQEYZ Spring 2 ($165)
DDHiFi Janus-E2020A ($199)
DDHiFi Janus-E2020B ($199)

Cayin N6ii (E01 motherboard)
MacBook Pro
Shanling M6 Pro
HiBy R3 Pro Saber


Songs:

Alex Fox
Pink Floyd
Buena Vista Social Club
Elton John
Stevie Ray Vaughan
Shane Hennessy
Jeff Beck
Dave Matthews


Technicals:

Adopting SVAS Technology—IKKO in-ear monitor uses Separating Vector Acoustics System technology, the precisely designed cavity structure makes the sound volume, reflection and diffusion angles, and the unit performance is displayed to the greatest extent in a limited space. This seems to be the de rigor of the day, making the cavity acoustically similar to a listening room. Many manufacturers do this, and I approve of this methodology.

Utilizing 1DD+1BA Hybrid Driver, the 32Ω 10mm Deposited Carbon Nano Dynamic Coil plus the Knowles 33518-unit hybrid driver makes balance the three frequencies (low, mid, high) according to Ikko. Made using resin and aviation-grade aluminum alloy in the sound cavity to achieve the physical frequency dividing effect. The shape can minimize mutual interference between the sound generating units and make the sound purer and more transparent.

Unboxing:

Coming in a sleeved outer paperboard box decorated with colorful images based around a cityscape, it is reminiscent of the recent Anime images of some manufacturers, but better to me. Labeled as part of their “Gem” series, the back has an exploded view of the unit, and some of the specs in a few different languages. Tastefully done.

Sliding the sleeve off you are met with another paperboard box, laden with more pictures on the front and the same nomenclature on the back. The difference here is that a thicker box slides out of one long side, while the other opens like a normal box. That inner thicker cardboard box (well done by the way) has a side lid, so you can pull on that the “extricate” the inner box from that secondary paperboard box. That inner box has a nice gold sticker stating, “Ikko Design,” and it clasps magnetically with a satisfying click.

Opening the lid, you are met with an MMR-type presentation, complete with exploded view of the OH1S, attachment of the cables and how to insert the MMCX cable. Each unit has a label, the left states “Gem Texture” and the right “Transparent Twin.” Also inset between the OH1S IEM’s is a lapel pin, which is a nice addition. Remove that insert, and after removing the instruction manual envelope, you are met with a pleather case, not unlike the wallets you used to purchase as a kid on vacation out west (USofA). Tucked between the tips and the woven case is the slim box for the cable. Next to that is thin plastic tip holder, with all on display. In total there are 18 tips, including three sets of Ikko’s own proprietary foam tips. All of the silicon tips are oblong in shape to match the oblong nozzle, a first for me.

A word of warning regarding the tips: MAKE SURE they click onto the nozzle area to seat them fully. Otherwise they may come off in your ear. I found out the hard way with the smaller foam tips…we shall simply leave it at that.

Build/Fit/Function:

The OH1S comes with 1DD+1BA Hybrid Driver, a 32Ω 10mm Deposited Carbon Nano Dynamic Coil plus a Knowles 33518-unit hybrid driver. Using resin and aviation-grade aluminum alloy as the sound cavity in the shell to achieve the physical frequency division effect, Ikko calls this Separating Vector Acoustics System technology, designing the cavity structure precisely, much like you would orient your speakers in the listening room. More manufacturers are taking the shell cavity seriously as a means to either tailor sound or ensure proper acoustics. I appreciate the time spent in R&D with this regard and can see it expanding in the future.

Made of three pieces, which is unusual other than the nozzle, the OH1S shell combines the inner part and nozzle (with a vent hole in the inside); a middle acrylic section in purple (for mine) and the faceplate in black, and “textured” like ripples or scales on the back of a Rainbow Trout (Oncorhynchus mykiss). The nozzle is oblong in shape as well, which is a unique one to me. The screen comes off as well, so be careful when using different tips. Extra screens are included in case you lose one. As mentioned above, you will want to ensure the tips are properly placed, especially the foam ones, with an audible “click.”

Fit in my average sized ears is nie-on flush, without pressure in my canal. Using a tip too large can cause a bit of discomfort, and the seal of the foam tips is among the worst I have had but do aid in deepening the bass response. For a proper seal and excellent fit, the large oblong silicon tips work. The cable lies over the ear, with a stiffness I am not used to of late, but it does not bother me like older Unique Melody cables used to. With really long ear guide sleeves, and a permanent soft bend you get good fit, even with glasses. The shape can be tailored a bit. The four-wire-in-two-strands is also amongst the stiffer cables I have used of late. Above the Y-splitter, the OCC silver plated wire looks to be of two strands, but three colors. A blue tint fades to copper along with the silver strand. The blue reminds me of heated copper, so I do believe it is for the visual aspect. Some microphonics is promoted due to the stiffness, but not much. Quality metal cinch strap, Y-splitter and jack in a dark copper color makes for a good-looking cable, by not drawing attention to itself. A reinforced sheath surrounds the MMCX connection, making for a solid fit.

Other than isolation, which I am blaming on the oblong nozzle, the fit, finish and build are excellent, if a bit economical.

Sound:

Summary:

From the previous iteration of the OH1, I liked the tight bass control, but wished for a bit more. Taut bass would be apt. The OH1S indeed gave me my wishes. While still tight in control, there is no bleed into the mids, but this does not mean a separation. All is tied together well, and there is very good separation of note. The thinness of sound, which came from the OH1 (not a bad thin sound) carries over, but with a bit more weight of each note. Distinct sounds emanate from within and placement of each instrument gives the illusion of spacing. Not the best, but not the worst. Switching to my Cayin N6ii E01, the sound jumped up quite a bit in quality. Source dependent, I would feed a good source into the OH1S to get the best out of it. Vocals come across as slightly lifted, especially male. Van Morrison’s strong vocal presence can be a bit biting on some IEM’s, but on the OH1S, the sound is succinct and detailed. Mids carry a bit less weight than the vocal presence does, making for a slight V-shape to me, what with the good but not painful treble extension. Nicely tuned, but not a “wow moment” of transformation. Sometimes (and in this case) that is a good thing.

More detail:

I mentioned how the OH1 was good with details, but a bit thin. I rate this due to the lack of a thumping quality of bass. While the OH1S does not have a thumping quality to its bass, it does have more than the previous iteration. The carbon nano technology makes for very fast decay as well, which could help to explain its lack of pure oomph. A slower decay would allow the low end to linger, and hence at least give the illusion of more depth. Tight control is also helped by the carbon technology, and spatial presence of the acoustic chamber. I do not mind the low-end treatment, for it does not bleed into the mids, which is a good thing in this case.

Electric guitar work such as Peter Frampton on Reckoner affords good depth to the mids as an example. The support guitar gives that depth needed to aid in placing the instruments properly. This in turn leads to good depth of soundstage. Allowing the instruments to flow through the soundstage, the mids are clear and fairly crisp. Not the detail monster such as the Cayin Fantasy or Moondrop Blessing2, but good, nonetheless. I go back to what I said in the summary, the OH1S does not offend in sound, but neither does it thrill. By that, I mean the mids promote a smoothness to them, which can come across as boring, but it isn’t. Wish You Were Here from the Pink Floyd tribute album shows that there is nothing boring here. Joe Satriani’s solo is divine in nature, and worth a listen regardless of listening pleasure. Rik Emmett’s vocals sound like a Guns-N-Roses version, but better without the edge. I like this version and think it does justice to Pink Floyd nicely.

Satriani’s solo can move into the treble range when he gets going, as can cymbal clashes. Not offending me at all, there is a sufficient push to make up a bit of the smooth texture laid down by the mids. Not in a disconnected way but tied together well. Sometimes an over-compensation is had leading to a disconnect. Here, the tie leads to smooth transitions, without stepping on those lower notes. Cymbal clashes sound slightly robotic and dissonant, but not like some I have had of late. Th whole is greater than the sum with the OH1S.

A good judge of soundstage that I used to use is closing my eyes and placing my hands at what I would consider an estimate of reach in all three dimensions. I used this on the OH1S and found a nicely shaped cube extending a bit past my ears, but not quite as high. Almost cubic to me, and of good shape. Placing of instruments was easy, especially with the black background without hiss between notes. Shane Hennessy’s Rain Dance is an extraordinary song for the listening but works extremely well for gauging placement and stage as well. His incredible talents of strumming and using the guitar as a percussive instrument allow you to gauge very well placement and layering besides stage. A very complex guitar song with which to start, that complexity lends itself to excellent spatial representation. If an IEM (or headphone for that matter) lacks in any direction, it is heard in a squishing of the sound. On the OH1S there is none. I find the song wonderful on most listening devices, and here as well.

Comparisons:

Ikko OH1S ($199) v CFA Honeydew ($249):

The CFA Honeydew came my way by private audition, and it was good. Many lamented it as a “rehash” of something else. So what. Most manufacturers fine tune their wares, and CFA is allowed that as well. Capitalizing on their excellent bass heritage, the Honeydew trounces the Ikko in that department. Moving towards the middle spectrum, the Honeydew presents very good details, and it is easy to hear the heritage of the Andromeda in it. I would rate the Honeydew as distinct and detailed, where the OH1S is smooth and detailed. There is also more push up top, but not as much as the Satsuma. If I had to choose one of these two new CFA models, it would be the Honeydew. As for the two listed here? If you prefer a bit better defining sound, melded together, the Ikko would fit the bill. If you prefer better bass, with more distinct details, the Honeydew would fit.


Ikko OH1S ($199) v CFA Satsuma ($199):

Same price. The toughest segment to me as well. The $200usd price is a cage match of excellent to very good offerings. But This gives the user many, many good options. Both listed here are good but for different reasons. While the Satsuma adds more detail than the Honeydew (closer to the Andromeda), it provides less bass. The Satsuma is an excellent detail monitor to me, and clearly (cleanly?) wins in that department. If you want a smoother signature, then the OH1S would be your choice. Bass is about the same, with the mid-bass push of the OH1S versus the deeper reach of sub-bass on the Satsuma (but not like the Honeydew). If you want excellent technical skills, the Satsuma is the choice. A smoother character (to me), then the OH1S is the choice.


Ikko OH1S ($199) v Thieaudio Legacy 4 ($195):

When Thieaudio first came about, it meant business. Drawing some of the best engineers out there, the Legacy line comes across as business. The L4 is an excellent monitor with gorgeous looks. Much more mid-forward in signature as well, the L4 provides the listener with deeper reach of bass as well as wonderfully toned mids and treble. More push up top as well, these two actually complement each other quite nicely. If you like smooth, the Ikko wins hands down. If you like a richness of tone and excellent details, the Thieaudio would be the choice. I often go back to the L4 to remember how good it really is. Smooth versus vibrant. Take your choice.


Ikko OH1S ($199) v BQEYZ Spring 2 ($165):

I really liked the Spring2 when it came out and will compare it to the Summer in an upcoming review. I called the Spring2 one of my recommendations at the price, and that still holds true. The rich tonality emanating from within aid in a very smooth, laid-back, but not boring signature. Think of comfort food, and that would be the Spring2. Just an excellent all-arounder to me. Better bass push, but with a bit of bleed into the mids, and enough up top to give that “fresh day” feeling. That bleed of bass into the mids aids in presenting the rich tone of which I speak. Warmth and grace, the Spring2 is still one of my favorites. V-shaped? Maybe, but I do not care. The Spring2 would be even more laid back than the OH1S, going further into that comfort zone. Want a bit liltier sound? The OH1S would be the choice. Richness that is of goodness? The Spring2.


Ikko OH1S ($199) v DDHiFi Janus-E2020A ($199):

The original Janus was and is an interesting tune. A bit smaller of sound stage, but offering good detail, it dovetails nicely into this segment. Good bass extension adds to its flavor of semi-tightly controlled mids, and a rolled treble that while not as smooth or rich as the Spring2 is nonetheless, a good listening experience. Take note, though. DDHiFi has retuned the Janus based upon our listening experience and offerings. Two very different critters. Of all the offerings here, the Janus E2020A is most like the Ikko, but with better bass, and a bit more veiled mids. Not bad mind you, but quite close.


Ikko OH1S ($199) v DDHiFi Janus-E2020B ($199):

Completely redesigned to make it a bit more premium, the Janus E2020B comes across as more V-shaped than the A-version. Deeper reach of bass, with a smidgen of bleed makes for a pleasant, crisp tone when combined with the better reach up top in the treble region. This is a breath of fresh air when compared to the A-version, and with the OH1S. If you want smooth laid back, then the OH1S is still the choice, but the E2020B has hit the sweet spot to me with their tuning, even if it is oriented towards “consumer version.” Smaller soundstage may put you off, but like the A-version and smoother OH1S is to comfort food, the B-version may be to an energy drink after a good workout, or before. I really like the E2020B if you cannot tell, and a review is forthcoming. Mind you, the OH1S is still quite good as well and it is nice to have choices.

Finale:

When I first heard the OH1, everyone said, “you need to listen to the OH10 if you like the OH1!!!” Well, no I didn’t, even if I really liked the OH1. That was enough for me for I liked what I heard in the OH1, even if it was a bit bass shy. The OH1S is a “redesigned” model with new innards, making for essentially a new model. But I would call it an evolution rather than a revolution. Taking the good parts of the OH1 such as the clarity of detail and smoothing the edges to make it a bit well…less edgy…makes for a smooth transition to the OH1S. Smooth and rich, but not muddy. Warm, but not warmth overall. A nice laid-back texture emits from within the designed cavity of the shells, and it comes across as pretty good. Going back and forth I can note the differences and similarities, but I’m not sure which one I prefer. I do think I prefer the open expansive nature of the OH1S more than the OH1, but I can clearly appreciate the heritage of the OH1 coming through. It is still one of my favorites.

The OH1S is good. Quite good, but its signature will surely turn some off. I mentioned how it doesn’t have that “wow effect,” like some. And this will hurt it when comparing to others. Some may find this boring, or lacking, but I would kindly ask them to audition it under the right circumstances, such as the end of a long day with a single malt in hand. It is then you hopefully enjoy Jeff Beck’s Brush With The Blues as I did.

I thank Ikko for providing the OH1S to me and hope that you all enjoyed this journey through my word salad verbiage. The OH1S is good enough to take a look, and be in consideration at this price point, which as mentioned is wrought full of choices.

Cheers.

Intro
I will refer to the Ikko OH1s as the Gems, in this review. The Gems are a set of IEMs which follow the successful Ikko OH10. The OH10s are a bass emphasised set of IEMs, which begs the questions, are the Gems an attempt at a counter-balance to the OH10s? Are they deserving of the name “Gems”.

Disclosure
The Gems were sent to me by IkkoAudio for review. You can buy the ITM01 here:https://www.ikkoaudio.com/

All opinions I express here are my own with no influence from anyone. No one has editorial control or influence over the contents of this review. I make an effort to ensure that I give the reader factual information. I would appreciate your feedback.

My setup for this review
I paired them with Samsung galaxy note 10 Plus and Fiio M11, as my source, and for amplification variably, The HAA FEE HA11, Fiio BTR5 and the Littlebear B4X tube DAC/Amp, mostly 2.5mm on high gain. I also used Amazon Music, but primarily UAPP music player.

Form, Fit and Function

Specifications:
Form: IEMs.
Brand: Ikko
Model: OH1s Gems
Drivers (x2) : One 10mm deposited carbon nano dynamic coil driver + One Knowles 33518 hybrid BA.
Impedance (Ohm): 32 Ohms.
Sensitivity (dB): 109dB.
Frequency Response (Hz): 20 Hz – 40 KHz.
Detachable Cable:
Length: - 1.2m

Composition: high-purity single crystal copper, silver-plated.

Connection to IEMs: MMCX

Connection to source Jack: 3.5mm TRS.

Form and Function

The package: The Gems come in a mid-sized book-like package. The package is very well packed so as to reduce the size, all of which are covered with a sleeve. Within the sleeve is a box which pulls out of the sleeve to reveal a sturdy construction. Within the box there are two layers, the top layer has the IEMs displayed and the lower is separated by an envelope containing the necessary documentation.



In the lower layer you are presented with three segments containing a nice pouch for your IEMs which do not offer much protection and a generous selection of tips, some oval in shape. In the middle layer you have a little box which contain the rather good looking if a slight bit memory prone, with an MMCX removal tool.

Form: The Gems are small and light compared to the OH10 Obsidian. The outer shell of the OH1s is made of a combination of aluminium alloy and resin. The casing feels solid in spite of the tiny size and lighter materials compared to the Obsidian. The Gems come in two colours, blue and grey with a purple insert (the set I have) which I rather like with its purple accent.



Fit: The small size and lightweight make the Gems almost physically imperceptible when they are in your ears. Isolation is quite good, although I have yet to try them outdoors, I imagine the good fit will cut out a lot of external sound but not the best at isolation.


Function: The Gems are not only comfortable they are a snug fit for me. The one unusual aspect of these IEMs are the nozzles, which are oval, hence the selection of oval tips referred to above. The cable is beautiful and effective, if somewhat slow to straighten up. It is not the most malleable cable. However, they are so nice looking, sometimes you forgive them for being functionally ideal.


The sound
In short if you do not want to read the whole review: The sound on the Gems is an acquired taste! Once acquired, the taste is magnificent. The Gems come across as neutral, highly resolving and effervescent, in other words they are not a mellow set but are revealing, and distinctly lively.

The overriding sense is of a highly resolving set, which can both call on deep bass as the track demands, mid range which is incredibly rich and forward, and a rather highly extended and occasionally spicy top end, this is where the acquisition of the unique taste of the Gems is required. The resolution makes you feel like you are playing your music on a high end system, the caveat here is if you are listening to well recorded tracks, these are TRUE Gems!

Bass
The sub-bass on the Gems lies in wait for the unsuspecting, it is not prominent but when the track demands sub-bass…..boy do they deliver! Here I am talking of no less sub-bass than the OH10 Obsidians deliver. The sub-bass is incredibly visceral and potent, again if recorded these IEMs will find the note, and they would even reproduce the unintended as long as it is recorded. You hear everything but above all the quality of the bass is (in fact every part of the frequency range) so well defined, it is just superb!

The same is true for the mid-bass, the Gems are so resolving that they pick everything up and present them beautifully. However, in relation to the mid-bass, the definition of the bass notes is spot-on and natural. The dynamic driver is precise.

Basso Demo Test - By Audiophile Hobbies:

This track can represent an indication of all frequencies, but the deep male voice here is so well depicted, I thought it would be a good demonstration of the capabilities of the sub-bass and mid-bass. On the Gems this track is truly magnificent

Zhao Cong - Moon Light on Spring River:

Moon Light on Spring River is a true sound check for sub-bass. Note the sub-bass at 0.56 seconds and 0.59 is inaudible on some earphones. Many earphones first register the sub-bass at 1 minute and 10 seconds. The Gems render the sub-bass at 56 and 58 seconds seconds with no sweat and remember these are no bass-head IEMs.

Midrange
The midrange on the Gems are a gem. This is not intended to be a pun, the midrange is very rich. All instruments plying these frequencies are richly delivered.

Both male and female voices are so beautifully delivered, guitars, saxophones, any instrument plying the mid-range just shines. As with the bass, the presentation is realistic, full and rich with detail.

Again, because of the revealing tuning of these IEMs, nothing is lost in the mix, including the sound of spittle in a mouth piece, the decay of a string or a broken reed.

Armik - Midnight Bolero:

The track is in the style of a classic Spanish guitar piece which shows how satisfying the Gems render mids. Multiple guitars, percussive instruments calmly give rhythm in the background, while the lead guitar expressively “talks” to us. The gems just deliver the sound effortlessly.

Highs
This is where the division between those who have acquired the taste for the Gems and those who have not, occurs. The highs are in most instances intense but satisfying. At the beginning of my testing, on occasions I felt this intensity went a step further and came across as sharp and even spicy. However, call it burn-in or brain burn-in I could not hear the spikes after the first week or so.

They really do sound great and highly resolving. This makes the Gems sound like they belong in another, a much higher, price range. However, you need to get used to or get past the occasions when the highs sound can get spicy to acquire the taste for the Gems.

Brian Culbertson - Sensuality:

The peripherals of this track highlight the truly magnificent heights the highs on the Gems can go. You hear the upper registers of the piano so distinctly and beautifully, add to that the cow bell, and shimmering chimes just add to the sprinkling of stardust, all beautifully rendered by the Gems.

Tim Bowman - Soul Dreams:

Frederic Chopin - Nocturne in E-Flat Major, Op. 9, No.2:

Imaging, Separation, Sound Stage
The fact that the Gems are so resolving means that you get clear and detailed delivery. The separation of instruments, layering, and stage go with the territory and they do not fail to give you the perception of the instruments positions. The sound stage is not exceptionally expansive, although the width of the stage is above average.

Conclusion
We are in this hobby not to hear the same type of sound or buy exactly the same sets all the time, there are times when we need to go outside our comfort zone. With an eclectic taste in music and sound signature, I am neither a bass head, nor a treble fiend, but what I do know is that once I “got it”, I really enjoyed listening to these Gems! For me these are TRUE GEMS. They are a fitting complement to the IKKO OH10s and it is a pleasure to have them in my collection.

Enjoy your music!

Ikko OH1s Review - Hidden Gem?



Intro

There are several models in the OH series which are highly touted, namely the OH10 as well as the OH1, at least from what I heard. Today I have the OH1s with me. Let's see if it’s able to hold out or stand out among the competition out there today.


Packaging

Not going to be talking much about the packaging as I've already made an unboxing video for it. You may check them out here
In short, I like the packaging very much, very premium and the bundled eartips are a very welcoming gesture. I have a very good unboxing experience.


Build and Comfort

The build quality of OH1s is very solid. It consists of aluminium and resin. Majority of the shell is aluminium. The size is also very small and it stays in my ear very comfortably and I have no issue wearing them for long hours.

When they’re in my ears, I totally forgot that I'm actually wearing an IEM. They are that lightweight. Provided that you are using it with the stock cable of course. Your mileage might vary depending on the cable that you will be using it with.




Source

Foobar2k -> RHA DACAMP L1 Lineout Cayin C5 -> OH1S
Apple’s Type C Dongle -> OH1S


Sound

Upon putting them in my ears, hitting the play button. I am instantly amazed by the level of details and technicalities that this little gem offers. It is highly resolving and it’s unlike anything that I have in my collection. For some, it might be a little too glaring, but i actually like the way it is, it is also possible that i’m not as sensitive to treble compared to others.

Tonality wise, I would describe them as very revealing and slightly lean overall, best to pair them with warm source. I like the detailed presentation of OH1s in general. Your mileage might vary.



Bass

• The bass coming from this little gem is very lean, at least to my ears
• Definitely not for basshead
• It is tight and fast,adequate quantity to ensure there’s still some room for fun
• As mentioned earlier, the bass is lean and naturally, it lacks some warmth and body
• The bass is fast and tight and it makes it very enjoyable on tracks on Slipknot’s Duality and System of a Down’s Chop Suey!

Mids

• Vocal is rather forward and rather intimate
• The vocal to my ears they are rather thin sounding and somewhat dry, but it doesn’t sound bad at all
• The upper mids might be a little too glaring for some, but I find them to synergize very well with such tuning.
• Overall, the mids is not this gem’s strong point

Treble

• Energetic and complement very well with the lean signature of this gem
• No signs of sibilance nor piercing high
• Smooth and energetic is how i would describe the treble
• Plenty or air
• Very good micro details

Soundstage/Imaging

• Soundstage is average to my ears
• Lacking in width
• Imaging is average,doesn’t really stand out for this price point
• Instruments separation is also average to my ears
• Despite having average imaging capability, i’m still able to pinpoint the instruments properly

Driveability

• Easy to drive and you will get acceptable volume level even off smartphone
• Benefit from better source/dac/amp
• Does not really benefit much from amping

Cable Rolling

• Cable rolling does not change the signature much but it does improve the note weight depending on the cable material used
• I found them to pair well with copper cable,it will kinda tame down the upper mids a little for those who find them to be too glaring
• Doesn’t really synergize well with SPC as it made it even brighter

Final Thoughts

When I first listened to OH1S, I found it hard to accept it due to the glaring upper mids and it’s highly resolving nature. However, as I used them longer and probably they kinda settled in (burned in), I grew to like its signature. It is airy and very detailed.

Now, who will not like this? I guess those who prefer a meatier bass response will not like OH1s, the bass on this little gem is lean, the dosage is just right and responds when it's called for. Nothing more, nothing less.

As for me, I like it personally. Who would I recommend this to? Someone who’s looking for a highly resolving hybrid IEM that doesn’t have the BA timbre and flat bass response. I will not recommend this to someone who prefers meatier bass response and also slightly darker tonality.

Overall, i will rate this IEM which i listened via my setup a 4/5

*A big thanks to Ikko for sending over this unit for me to review. I receive no compensation that will affect my evaluation towards this IEM.

If you guys are interested, head over to Ikko’s store to grab this unit!
Webstore
AliExpress Store

IKKO OH1S
I would like to thank Rebecca from IKKO Audio for supplying this review unit.

The OH1S is the latest model in the OH series from IKKO, following on from the OH1 and OH10. Like the previous models, it is a dual hybrid. It features a new 10mm composite dynamic driver with a carbon nano diaphragm paired with a Knowles 33518 balanced armature. It also has IKKO's "Separating Vector Acoustics System" (SVAS) technology, which is a unique cavity design which Ikko claims “improves volume, reflection, and diffusion angles". The interface is MMCX. The OH1S retails for $199.

The presentation is superb. The outer cover features an illustration of a cute girl dancing in front of a night-time cityscape while listening to her music. Inside this is another slip cover with a colour image of the IEMs on a graphic background with the name "GEMS" below. Removing this reveals the actual box which is black with a linen finish and a gold block bearing the words "IKKO DESIGN". Upon opening the box, you are greeted by the IEMs sitting in a card layer with graphics and an IKKO branded metal badge. Below this in a further layer the cable is stored in a simple black box along with the leather storage pouch and nine pairs of eartips.

In all the contents comprise:
* IKKO OH1s IEMs
* Silver plated single crystal copper cable
* 6 pairs of silicone tips
* 3 pairs of foam tips
* Leather storage pouch
* 1 pair replacement filters
* Tweezers for filter replacement
* IKKO branded badge
* Documentation

This is an impressive and comprehensive presentation.

The IEMs themselves are constructed from metal and resin and are available in two colours, purple/grey and blue, which, in the gemstone world might be thought of as "amethyst" and "tanzanite". I received the purple/grey version. The grey metal faceplates have a textured hammered surface and the inner part is formed from resin and is black. Between these elements there is a layer of a rich amethyst colour resin. There are two vent holes for the dynamic driver, one in the centre of the inner face and another on the top edge. The nozzle is unusual in that it has an oval cross section, which accepts the oval shaped silicone tips.

The cable is a 2-core design. The material is single crystal copper and is silver plated and the strands are decorated with red and blue accents. The 3.5mm plug is straight and in black metal with white graphics and there is a cylindrical Y-split and chin slider in black-coloured alloy.

The OH1s was tested with an Xduoo X20 DAP and a burn in period of 100 hours was allowed to settle down the components. A Huawei smartphone and a CD player were also used during the evaluation. The small foam tips were used which provided a comfortable fit and a good seal. Adequate volume was available from all sources but a higher quality resulted with increased power.

First Impressions
The OH1S displayed an unusually transparent and detailed sound with excellent definition. The bass was firm, well-textured and deep, mids were neutral and expressive and treble was clean, bright and extended. There was a very large, airy and spacious soundstage and the profile was linear tending towards a mild W shape. Music was presented in an exciting fashion with superb dynamic range, fast transients and a lively immediacy. The timbre was very natural and there was an overall feeling of refinement and the coherence between the two drivers was seamless. I did find the OH1S unforgiving of poor recordings and that it performed at its best with high quality material. It was also very revealing of the source and I found the neutral profile of my Xduoo X20 a perfect match for the OH1S, preserving its inherent properties.

Bass
The bass was generally linear in nature and reached deep with a good sub bass presence, but it was not overdone and remained in balance with the rest of the spectrum. However, a little more sub bass depth would have been welcome. Mid bass had a solid kick and the transition into the mids was smooth with no evidence of bass bleed. The texture and resolution were of a high standard.

Corciolli is a Brazilian musician specialising in New Age and World music. "Pegasus" appears on his album "Lightwalk". A punchy bass synth sequence accompanied by piano begins the piece and impressed with its immediacy. Later bass guitar and drums join in. The bass guitar was powerful and very well textured and the drums had a notable impact. The transient attack on this track was excellent.

Rachmaninov's Symphonic Dance No.1 received a stunning interpretation from the Minnesota Orchestra conducted by Eiji Oue. The OH1S delivered a thrilling rendition with an almost tangible "live" feeling. The bass drum strikes were clean and incisive with a natural decay but free from boominess, and possessed depth and impact. The power of the orchestra in full flow was palpable in the astonishing Reference Recordings production.

Jean-Michel Jarre's "Oxygene Part 19" explores the full range of his arsenal of synthesisers. At about the half way point a synth descends deep into the sub bass. The OH1S reproduced this with great texture and resolution although a little more depth would have been preferable. This is followed by a fast bass line where each note was clearly defined and reproduced with speed and precision. This was ideal material for the OH1S.

Mids
The OH1S really shone in the mids. They were open and detailed and combined excellent separation with great clarity. The timbre of instruments was very natural and there was a good sense of space.

"Slipping through my fingers", from ABBA's "The Visitors" features a lead vocal by Agnetha. Her voice was clear and precisely placed in front of the backing vocals and the emotion of the lyrics was conveyed directly with excellent diction. The separation in the backing vocals was excellent and the electric guitar solo in the bridge displayed aggression and impact in equal measure.

The superb interplay between the guitars in "I'll see you in my Dreams" by Chet Atkins and Mark Knopfler from the album "Neck and Neck" demonstrated the midrange timbre and detail of the OH1S and showed what an entertaining sound it could produce. Atkins's chordal work combined adeptly with Knopfler's Django Reinhardt-like solos with each note clearly defined with wonderful rhythm and timing and producing a joyful toe-tapping result.

In the beautiful 1977 recording of Schubert's String Quintet, the Melos Quartet is joined by Mstislav Rostropovich. The OH1S demonstrated its fine timbre with the various instruments sounding natural and vibrant, and the concentrated atmosphere of the Adagio was a joy to hear. The contrast of bowed and plucked strings was realised authentically with a perfect balance between the players and a fine reproduction of the ambience of the hall.

Treble
The treble was clean, clear and detailed, exhibiting good extension and being free from harshness or sibilance. It was a little brighter than neutral with an attractive airy quality and remained smooth even during energetic passages. Only occasionally on certain material there was a little extra brightness.

"Mausoleum at Halicarnassus" is the fourth movement of Stuart Mitchell's "Seven Wonders Suite". After a lengthy introduction featuring solo flute, a rising string motif is embellished with a bright triangle. The initial strike and subsequent decay were beautifully captured by the OH1S in this lovely performance by the Prague Symphony Orchestra under Mario Klemens. The flute sounded natural and airy and it was even possible to hear the intake of breath by the flautist. The high string accompaniment was also beautifully conveyed with superb delicacy, detail and timbre. The Knowles BA really showed its class here.

"Starry Night" from "Horizon" by Ed Van Fleet is an atmospheric evocation of looking up at the night sky. The smooth string synth patches were redolent of the expanse of the scene and the accompanying delicate shimmering effects were crisply depicted on the OH1S, displaying good treble extension and fine detail. The contrast between the high frequencies and deep bass tones was enchanting.

“The Glass Hall” from “White Winds”, the third album by Andreas Vollenweider, is an ideal piece for evaluating treble extension, detail and separation. Delicate crystalline sounds filling the soundstage begin the track and the precision and clarity delivered by the OH1S were remarkable with the finest details being revealed. In a typical complex production from the Swiss master of the electric harp, woodwind added colour and a large percussion section provided intricate rhythmic patterns, all of which were presented clearly and harmoniously by the OH1S in an entertaining fashion.

Soundstage
The OH1S displayed a very expansive soundstage with excellent imaging, layering and separation. It was easy to follow individual strands in orchestral music or bands, and vocals were projected well, standing out clearly from the accompaniment. The ambience of recording venues and studios was reproduced accurately.

Delius's beautiful "Walk to the Paradise Garden" received a luminous reading from the Philharmonia Orchestra under Owain Arwel Hughes. The orchestra was laid out convincingly and the interplay between the various woodwind instruments as they took the main theme in turn was clearly depicted with each instrument placed precisely in its own space and position in the image.

"Walking in Space" is part of the "Interstellar Suite" by Amin Bhatia. It is a cinematic work performed on synthesisers resembling a soundtrack to an imaginary film. It begins with sound effects and comms describing the opening of an airlock and an astronaut beginning an EVA. The binaural effects were stunning on the OH1S with a vast ambient space and the stereo imaging in the ensuing instrumental section was remarkable.

"I Robot" is the title track from Alan Parsons Project's second album. A phased synth drone accompanied by wordless female vocals sets the scene. Gradually more tracks are added, a synth sequence in the left channel, percussion and another sequence in the right channel. Choral parts join followed by electric guitar. Soon a bright cimbalom solo is added and throughout, the OH1S managed to display all these elements clearly with excellent layering, a wide stereo panorama and pinpoint imaging. This was very impressive.

Comparisons
Tin Hifi T3
Like the OH1S, the T3 is a dual hybrid, it employs a 10mm composite DD for the low frequencies and the same Knowles 33518 BA for the high frequencies. It is very well made, with a metal barrel-shaped housing and MMCX interface. The stock cable is especially impressive. In traditional Tin Hi-fi style, it has a neutral/bright profile but the sub bass is elevated. The soundstage is large and well-proportioned and detail retrieval is high. The OH1S has a broadly similar character but has a superior staging, more detail, and a better transient performance. It manages to combine musicality with an accomplished technical performance and is a more complete product.

TRI i4
TRI's i4 is another 1DD + 1BA model with the Knowles 33518 unit, this time coupled with a 10mm composite dynamic driver with a bio-cellulose diaphragm. The build quality is excellent and the subtly contoured earpieces are very comfortable. It has a warm to neutral profile which has a vintage "analogue" sound with a slightly recessed midrange and is very attractive and relaxing. The staging is expansive and the treble is smooth yet fairly well detailed. The OH1S is cleaner and more assertive in nature with a wealth of detail, better imaging and a more extended top end. It also has a more exciting and involving presentation with a more forward midrange.

HZ Sound Heart Mirror
The Heart Mirror is a single DD model with a "carbon nanometer" diaphragm. It has a full metal jacket with a polished finish and a 2-pin connection. It performs well above its price bracket and majors on technical aspects with high levels of detail, a neutral/bright signature and excellent timbre. The OH1S matches it in all aspects and improves on it with a much more extensive soundstage, faster transients and a more powerful bass and presents music in a more exciting and involving fashion. It is, if course four times the price of the Heart Mirror so this must be taken into consideration.

Conclusion
With the OH1S, IKKO have managed to produce a neutral, "reference" tuned IEM which also has the entertainment factor normally associated with V-shaped models. It is a powerful combination placing music-making as its priority and imbuing music with a "live" feeling. The tuning here of the Knowles 33518 is the best I have heard and has a natural timbre which matches the clean output of the carbon DD perfectly, resulting in great coherence. This tuning suits all genres, reproducing music with life and energy. The extensive soundstage is another major feature with superb imaging, layering and separation. The only small criticism would be that the sub bass could benefit from a little more depth and extension. Do bear in mind that the best results are obtained with a high quality source and recordings. If you are in the market for a neutrally-tuned IEM in this price range then do not hesitate.

TONALITY: 7.5/10
TECHNICALITIES: 8.4/10
CONSTRUCTION-DESIGN: 7.5/10
SOUND VALUE: 7.8/10

INTRO

IKKO is a company that offers different type of audio products including portable dac-amp, audio cables and desktop speaker (in the futur), but that specialize in earphones offering like their best seller OH1 and OH10 hybrid iem. All IEM from OH serie use a single dynamic driver plus a Knowles balanced armature, and while the OH10 upgrade was mostly about shell material change (full copper) that slightly inflict on sound rendering, the latest OH offering, the GEMS OH1S, have a whole new dynamic driver and different tuning.
Since the OH1 and OH10 tuning was very well balanced and dynamic, did the new tuning choice is good news or bad news? Let's find out in this review.

PACKAGING&ACCESSORIES



As always, the boxing presentation is very tasteful with IKKO, while it uses manga’ish imagery, it isn’t waifu, it’s more creative and playfull. The whole package design is carefully thought and more than worthy of it’s price range. In term of accessories, you have a generous amount of ear tips, a so so cable and a so so leather carrying pouch. If you find the ear tips strange, it’s because of the oval nozzle of the IEM, which is a questionable design choice I will talk about later.

CONSTRUCTION&DESIGN

IKKO OH series was all metal until the GEMS which is about half metal half plastic, which inflict on lighter weight. The size is drastically smaller than older siblings too, about 2 times. As well, gone is the 2pin connector for an MMCX one. The housing design is supposed to use special acoustic components to improve the overall sound, but due to very different tuning, it’s hard to make any conclusion about this lower distortion acoustic theories.
Fact is : the OH1S look and feels cheaper than OH1 and OH10, while it’s smaller, the awkward oval nozzle shape make the fit more capricious...especially with included ovni silicone ear tips. Sure, it’s way smaller so at the end you don’t feel the IEM as much, but with my ears shape, the OH1S doesn’t stay still. My ears don’t have oval hole but round one.



I don’t know what to think about the design choice of this OH1S, apart from that IKKO seems to give too much thinking about the design exclusivity and not enough about proper sound production. The cable included is underwhelming and something we would expect from a KZ IEM, not a 200$ one.



While the package and all superficial aspect of it is impressive, the practicality of the product isn’t. This nozzle shape choice was an error that will pull off a lot of potential users.



SOUND IMPRESSIONS
(using Xduoo X20, Xduoo XD-05plus, Audirect BEAM2 and LG V30)

TONALITY :
Mature neutral with lean light bass, smooth mids and crisp treble. Timbral balance is organic, and overall presentation is near analytical due to extra emphasis of highs that is the most energic part of the spectrum.

TIMBRE :
Thin with good transparency, realist but slightly clinical, the texture is there but not boosted.

RESOLUTION :
Above average, apart from bass that can be hard to see (or feel), it’s very clean and detailed but some areas feel scooped.

SOUNDSTAGE :
It’ all about deepness here, which is good due to the clean bass and black background. Wideness is subpar for the price and tallness isn’t really there, in other word: the sound feel a bit stock in your head.

IMAGING :
Quite good, more in instrument placement and accuracy, not so much in ‘’vertical’’ amount of sound layers. Though instrument separation isn’t the widest, it’s clean and accurate.

BASS :
Lean, very very lean, but well extended in a dry, bodyless way. You can hear the rumble and lower bass line quite clearly, but it’s mostly due to texture and definition. This will not affect the tone of electric bass, but acoustic bass will struggle to sound right and not distant. Control and articulation is quite good and no surprise that you don’t have any bass bleed cause their no slam nor kick weight, again, it’s more an ‘’image’’ of sound than a proper low end that use air to make sine wave. Personally, this type of bass makes me listen music in a overly ‘’cerebral’’ way, emotionally distant but intellectually curious. This low-end presentation is not for bass lover, even those that like it balanced and not boosted, Hzsound Mirror feel like a basshead IEM compared to the OH1S. Some monitor speakers have similar bass to this, or think about a less bodied and textured Sony MDR7506 bass and your not far from it.

MIDS :
Smoothly bright, gently boosted, inoffensive yet vivid enough and well resolved, this is pure balanced armature mids done right. No sign of sibilance, a bit organic and far from being thick, lush or romantically colored, the mid-range doesn’t try to hook your attention and is deadly serious in a good way we can say. Female vocal are particularly well done, less aggressive than older OH models, no sign of sibilance and very clean presence without over abusing pina gain. What the mid-range lack is surely due to it’s need of lower harmonic, the weight isn’t their at all, as well, it isn’t very open and quite intimate in rendering: no wide sound layers floating around, it’s all pin-point and centered, so, everything sound kinda distant without being recessed, vocal being an exception as well as saxophone. Piano sound a little artificial, but this change when you go in high register, in mids the lead attack isn’t hit but shot at you, since the piano use hammer to produce sound this ain’t right. Violin is even worst because it doesn’t improve in the high register, timbral balance just doesn’t work for it.

TREBLE :
While everything is rather smooth, the treble take it’s revenge and inject a good dose of energy to overall lean tonality. It had air and space too, which is great. But it can feel a bit detached some time, lacking fullness and complete extension to offer natural decay and sparkle. The attack is very fast and snappy and level of micro-details it dig is quite good...but i feel I have heard this treble in alot of multi BA or Hybrid, and to be honest it doesn’t impress me anymore. It’s a bit capricious, rarely it will go shouty but when it did it cancel any emotionality in me. Thats the thing, without sparkle the upper highs are a bit dull, and here it cut fast in extension so it scoops some important sound info find in natural resonance.

TECHNICALITIES:
Pretty pretty good. All crisp and thighs. The fast attack that is well controlled, with good snap. The resolution is clean, which is a big plus for proper imaging. Bass control is good and texture, resolution too though sometime it's distant in the back. The OH1S put its technicalities upfront to achieve a reference mature tuning, so acoustic properties are excellent.

Side notes:
These do not benefit from big amping. Cables upgrade can thicken a bit the sound but doesn't change anything drastically. Using non-oval ear tips can help to open the sound a bit, so don't lose hope with the one included!


COMPARISONS

VS IKKO OH10 (1DD+1Knowles BA-180$)

Unlike the OH1 and OH10 which are similar, the OH1S isn’t at all, well, apart from BA timbre to some extend.
TONALITY is colder and more neutral as well as smoother in mid but more emphasis in treble up to 10khz. OH10 is notably more bassy and has an overall thicker timbre and weightier dynamic.
TIMBRE is more artificial and bright.
SOUNDSTAGE is notably smaller but a hint deeper, it’s less holographic and circular.
IMAGING is cleaner and more accurate and precise.
BASS is a ghost compared to OH10, a ghost that doesn’t haunt you, way flatter and less natural.
MIDS are smoother and less forward, less bodied, cleaner and more detailed.
HIGHS are sharper and more snappy, better controled but not as well balanced as OH10.

All in all, the OH1S make me appreciate my beloved OH10 even more. Even if the resolution isn’t as good as OH1S.

VS SEEAUDIO YUME (1DD+2 Knowles BA-170$)

TONALITY : Warmer, more bassy, smoother Harman target vs crisper diffuse field for the OH1S.
TIMBRE : Thicker, more natural, less dry and bright, darker and less textured.
SOUNDSTAGE : Notably taller and wider, more holographic and out of your head but less deep and clean.
IMAGING : Higher amount of sound layers, less compressed but not as clear in instruments cue and separation.
BASS : More sub-bass boost, thicker body, warmer definition, more weighty slam and better low extension. Sub have more rumble and kick drum are punchier, but bass isn’t as tigh, lean and clean.
MIDS : Fuller sounding, more boosted in presence, lusher, female vocal are more upfront, timbre is more natural, piano note are more weighty, clarity isn’t as high, attack is less edgy.
TREBLE : Smoother lower treble, more organic, fuller and warmer in timbre, less metallic sounding but a bit less snappy and brilliant than OH1S.

All in all, Yume tonality is more relaxed, lusher, smoother and more enjoyable, while OH1S sound colder and more technical, with higher resolution and better attack control.

CONCLUSION

For me, Audiophile hobby is all about enjoying musicality before technicalities of my music, with the IKKO OH1S, it's all about technicalities to a point some will find it too clinical sounding, other lacking bass and fun. While the OH1 and OH10 find the organic balance between lush tonality and weighty dynamic technicalities, the OH1S choose to focus on high resolution and neutral tonality. This mature tuning isn't mass appealing and will please a niche market for those that enjoy neutral diffused field tuning. If you search for fun, Harman target or balanced bassy tuning, the OH1S isn't for you, but if you want to enjoy your music without any blanket on it's resolution, any boost in it's bass or warmth and density in its timbre, this might be the unique GEMS you were waiting for!



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PS: Big thanks to IKKO for sending me this review sample and letting me share my honest unbiased thoughts.
You can buy the GEMS OH1S for 199$ Here.

For more honest (and sometimes grumpy) audio review, give a check to my website here:
https://nobsaudiophile.com/

Executive Summary​

The Ikko Gems OH1S are slightly warm, organic sounding 1+1 earphones with good midrange resolution and note definition that, in the opinion of some, deserve a bit more slam and sub-bass extension.

This review was originally posted at www.audioreviews.org

Introduction​

First was the $139 IKKO OH1, which I analyzed. It had premium build, a healthy bass, but also an upper midrange glare that made me give it away to a Head-Fier over a coffee.

Next came the $199 OH10 with a V-shaped signature so well done that it pushed the model onto some best-of lists, including our own Wall of Excellence.

And now there is the $199 IKKO Gems OH1S, which according to some forums, early adapters are selling off in panic over a lack of bass.


Hey, wait before you make yourself unhappy – and read the whole article. The IKKO OH1S is a keeper. And that despite the different tunings of these three models which feature a 1+1 configuration, that is 1 dynamic driver and 1 balanced armature driver. The first two had large shells and the IKKO Gems OH1S has very small ones. Here you have your first huge bonus points (unless you fancy big plugs in your ears).

Specifications​

Physical Things and Usability​

In the box are the earpieces, the cable, a set of IKKO I-Planet foam tips, a set of oval silicone tips, a storage wallet, an IKKO pin, and the paperwork.

The IKKO Gems OH1S shells are premium built with mostly aluminum alloy and some resin, and they feature one of the companyʼs trademarks: oval nozzles, which help forming any eartip into the cross-sectional shape of your ear canals.

The shells are rather small and light compared to the original OH1, look and feel great, sit firmly in my ears and are very comfortable. The small size of the earpieces is certainly a huge asset. Isolation is not the greatest for me.






I typically do not write much about cables, but the included one is great for me: spindly, wiry, light. Coated with hard pvc, it has the right stiffness for me and is not rubbery at all. Great in the days where cables are more and more becoming ropes pulling our ears down. Less is more, also in this case.

Tonality and Technicalities​

Testing and Measuring Details

Equipment used: iPhone SE (first gen.), MacBook Air; ifi Audio nano iDSD Black Label with IEMatch, Hidizs S9 Pro, AudioQuest Dragonfly Red/Earstudio HUD100 w. JitterBug FMJ, AudioQuest DragonFly Cobalt, Astell & Kern PEE51; grey stock tips, IKKO I-Planet foam tips. 75 hours of break-in.


Co-blogger Alberto already gave you his thorough account of the IKKO Gems OH1S, and I principally agree with him. In contrast, the internet was full of criticism such as “no bass”, “narrow stage”, “thin vocals”, “peaky”…people who had purchased the OH1S based on their experience with the V-shaped OH10 put their set up for sale.

My rec: buy one off them for cheap.

First, the IKKO Gems OH1S is NOT the OH10, both are tuned completely differently, and one is not meant to replace the other. In fact, it is worth having both. The OH1S is the evolution of the larger and really peaky OH1. There is obviously confusion in the naming convention and IKKO could have avoided this by attributing easily distinguishable names to their different series.

To my ears, the IKKO Gems OH1S is a lightly off neutral, marginally warm sounding iem with a slightly bright tilt. As you can see in the graph, that pinna gain is <10 dB (“screamers” typically have 13-15 dB), and the bass looks very linear with a bottom roll-off…but most of that rolloff is an artifact of my coupler and it appears at every one of my measurements. It is just that the low end is not exaggerated, unlike in most other iems.




And yes, there is sub-bass extension, it is not the world’s biggest but it is there and enough (and maximized with the foams). We are used to strong kicks that are pleasing but not natural. The IKKO offer a good punch, too. Bass is not the fastest or tightest, but it is clean. Classic dynamic driver.

As to midrange, it is not thin but is lean, and in a positive way. Think of floorstanders and their lack of “fatness”. Vocals are lean and somewhat dry – but they are not pushed back as in a V-shape. They are forward and intimate, which gives you a listening sensation that is rather rare.

Treble is a mixed bag. Lower treble is held back a bit so that cymbals, although being crisp, sit behind in the 7 kHz region. That narrow peak at the transition lower/upper treble compensates for that but can be a bit strident for some; it comes out, for example, in very high violin notes. But that also adds good air.

You shuffle all of the above around when using the included I-Planet foam tips. These little cannonballs (look like such) fill my ears completely. In my perception, they increase bass and move the vocals back, which results in increased depth and deeper staging.

Apropos staging, I cannot confirm the reported lack of width. It is perfectly average to my ears. Spatial cues is great, particularly with the foams. Resolution and separation are also average for this class. Stage can become crowded with many musicians or when much is going on. Another big strength of the OH1S are the crisp attack.

Timbre wise, the IKKO Gems OH1S is sonically closer to a single DD than to a BA multi. It offers a rather organic sound, which is not if its biggest traits.

So, why would you not like the IKKO Gems OH1S? If you need a (really) strong bass and if you cannot handle the bit of midrange glare resulting from the relatively flat low end.

IKKO Gems OH1s and OH1 Compared​

You can guess the differences between the original OH1 and the OH1S when looking at the graphs. The original had a more boosted low and but also a higher midrange including that grainy upper part. The OH1 did not sound bassier as the human ear hears the whole frequency spectrum in context. But it was strident in the upper midrange to my ear. The OH1S has a more civilized upper midrange may still have some occasional glare triggered by the neutral low end.





For those who want to see a comparison between the OH1S and OH10…nope that’s pointless as both are different iems. The OH10 are V-shaped in sound, and the earpieces are huge and heavy. Complementary designs in all aspects.




OH10 (right) and OH1S.

Concluding Remarks​

Admittedly, I was lukewarm about the original OH1over its hot upper midrange. And I was initially sceptical about the IKKO Gems OH1S because of that flat bass tuning. But, bass is plenty imo, balance is there, only that sub-bass rumble may not be enough for some. Nevertheless, if you are looking for a bass bomb, this iem is not for you.

My ears really got used to that signature very fast and started enjoying it. And what adds to the pleasure is the small size of the shells which provide comfort, as well as that minimalistic, attractive cable. So yeah, no reason to sell yours.

Until next time…keep on listening!

Disclaimer​

The Ikko Gems OH1S were provided by Ikko for my review and I thank them for that.

Get the Ikko Gems OH1s from ikkoaudio.com

Introduction: Ikko Audio has released several highly-acclaimed hybrids in the past several years, with the OH1 and especially the OH10 being frequently found amongst reviewers’ top recommendations for the $100-200 price range. In for review now is their latest effort, the Ikko OH1S Gems earphone. It shares the 1DD+1BA setup of Ikko’s prior hybrids, but it eschews the warm V-shape tuning of its older brothers in favor of a neutral-bright tonality in keeping with its moniker.



I would like to thank Penon Audio for offering a sample of the Ikko OH1S in exchange for my honest review. You can purchase a copy for yourself here at an MSRP of $199. The specifications are as follows:

• Frequency response: 20Hz-40kHz
• Impedance: 32Ω
• Sensitivity: 109dB/mW
• Connector: MMCX
• Plug: 3.5mm straight plug
• Cable length: 1.2m

Packaging & Accessories: Ikko has adorned the outer box with Japanese anime-style artwork, but the packaging itself seems to have instead been influenced by the “Russian doll” aesthetic, having not one but two outer cardboard sleeves to be removed before the box itself comes into view. The packaging is actually quite high-class, probably the most luxurious I have experienced in the price range. Within the box the two IEM units are encased in a cardboard layer with rather whimsical artwork, demonstrating the need to connect the MMCX cable to the IEM socket, as well as offering an exploded view of the IEM construction. Also, for some reason, there is a tiny medallion.



Underneath this layer lies the accessories, which include what appears to be a genuine leather storage pouch, the stock cable (somewhat springy unfortunately), an MMCX tool (kudos to Ikko for this!!), spare filters, and six sizes of silicon tips as well as three sizes of foam tips.



However, these are not any ordinary tips. Rather, they are elliptically shaped, as are the nozzles of the IEMS themselves. While the OH1S is not the only IEM to opt for this feature (the Beyerdynamic Xelento and Apple AirPods Pro come to mind), it is unique enough that tiprolling is not much of an option here as ordinary tips will be very unlikely to seal to the nozzles properly (and in fact I wonder if some of the more negative impressions of the OH1S are a result of such a mismatched tip situation). However for my ears the elliptical tips provide exceedingly excellent comfort, and thankfully Ikko has included quite a variety of sizes in order to accommodate various ear anatomies as much as possible.



Build & Comfort: The mixed metal and resin of the OH1S shells definitely provide a unique appearance, albeit one that I personally do not find as premium as their prior efforts. However, they are both extremely lightweight as well as quite small and very ergonomically contoured, and the result (at least for me) is some of the best comfort available on an IEM. They tend to have a fairly shallow fit and insertion, meaning that they are a good option for those who find deep insertion to be uncomfortable or problematic.



On the negative side, careless insertion can result in mild driver flex — however proper technique entirely alleviates this for me. Isolation is below average. In addition the MMCX connectors spin extremely freely, causing a minor nuisance of repositioning them each time they are inserted and also provoking some doubts about long-term durability.



Signature: The OH1S has a bright neutral-ish signature, although actually I personally find it to be more accurately described as a very mild W-shape, with slight elevations in the midbass, the upper mids, and the lower treble. The restrained warmth in the lower mids is nicely balanced with the slightly bright upper mids and lower treble, and all things considered it is quite a coherent tuning for a hybrid. The only things I would nitpick tuning-wise are the rolled-off subbass and the slightly aggressive clarity bump around 5-6K that can come off as a bit edgy at times.



Bass: Aside from the subbass rolloff just mentioned the bass region is very close to ruler-type flatness, with just a slight bump in the midbass that carries over linearly all the way into the lower mids. There is a slight bit of rumble remaining in the subbass, but of course those looking for a visceral impact such as could be found on its big brother the OH10 will definitely not be satisfied since this is unmistakeably a reference-type presentation. However this does enable very good speed and tightness, and texture is quite good throughout as well. As long as reference bass is what you ordered from the menu, I think you’ll be very pleased with the dish you are being served.


Mids: I really like the mids on the OH1S. The small amount of warmth in the lower mids has been allotted extremely judiciously, giving just the right amount of body to instruments and male vocals. There is a lot of texture and detail throughout the midrange, and timbre is very natural. Male vocals are perhaps a bit recessed especially in comparison to the more forward and energetic female vocals which result from the upper mids push, but I don’t find the overall result to be imbalanced. Others have reported that the OH1S has thin note weight and tonality, but personally I don’t find this to be the case at all (again, I have to wonder whether these people tried to use standard tips and thus didn’t obtain a proper seal). Everything in the mids to me is in its proper place, and done quite well given the price bracket it competes in.


Treble: The treble on the OH1S is a bit of a mixed bag. It is definitely biased toward the lower treble, especially the peak around 5-6K. On the one hand this gives the OH1S extremely good clarity, and in general the treble is extremely resolving and microdetails are really brought to the fore. On the other hand, some tracks can have a bit too much glare in them for my taste. Following this peak there is a quite noticeable drop off that helps the OH1S to otherwise avoid provoking fatigue, and while there is pretty good presence from 11K-14K it rolls off sharply after that, and so there is not a whole lot of air in the presentation. There is also at times noticeable BA timbre, and overall dryness and a fairly quick decay also somewhat mar the naturalness of treble.


Soundstage & Technicalities: Technicalities here are also quite a mixed bag. On the one hand resolution and especially microdetails are exceptionally good for the price point. Imaging is also quite tight and the OH1S localizes very well. But on the other hand the soundstage is very problematic, with only average width and depth but above all a serious lack of height. This leads to a dearth of layering and separation, often even to the point of congestion. This is in my opinion a big blow for an IEM that targets a neutral-reference profile.



Comparisons:
vs. NF Audio NA2+: At an MSRP of $169, NF Audio’s NA2+/NM2+ seem to be the most natural competitors for the OH1S’ neutral-bright type of tuning despite the fact of the latter being a hybrid while the former are single DDs. In terms of construction, the NA2+ takes the crown with its aviation-grade aluminum housing. On the flip side, the OH1S definitely has the better fit and comfort with its more ergonomic shape and much lighter weight. As far as tuning, the OH1S hews closer to neutrality than the more U-shaped NA2+. The NA2+ definitely has a more impactful low end with much less subbass roll-off, but it also has a more aggressive boost in the upper mids — those who found the NA2+ to be on the borderline with its edginess there will likely prefer the OH1S. When it comes to technicalities, the OH1S probably wins as far as raw resolution, and with the help of its BA it does a slightly better job bringing microdetails to the fore. However the NA2+ absolutely destroys the OH1S in terms of soundstage, layering, and separation. Imaging is close to a draw, though it might be a bit more precise on the OH1S.


Conclusion: I have to applaud Ikko for having the courage and interest to branch out and experiment with other sound signatures, rather than tiredly rehashing the same one that initially brought them acclaim. In some ways their foray into a neutral-type presentation has been successful, with a fairly competent tuning that really showcases the highly-resolving nature of these IEMs. However I feel that OH1S could have used some more work, as the lack of air and poor soundstage and separation do tend to bottleneck it from achieving its full potential. The OH1S comes frustratingly close to being truly outstanding, but as it is unfortunately it’s hard to recommend, especially at the full MSRP of $199 when the NA2+/NM2+ exist at $169 with much more competent and well-rounded technicalities — which are for me the sine qua non of neutral monitors.

Introduction –

ikko is definitely a company I’ve been meaning to work with for some time. They have an alluring range of hybrid IEMs and some snazzy portable DAC/AMPs too. In particular, the company is known to offer innovative form factors with regards to both of these, and their IEMs too offer a striking abstract aesthetic. A few years back, the company released the original OH1 that originally put the company on the map. This was a dual-magnet structure Ti DD + Knowles 33518 BA hybrid monitor that many lauded for its bass performance. The OH10 released last year used the same driver setup but implemented a pure copper acoustic chamber in addition to optimising the nozzle diameter to reduce resonances and distortion. The OH1s is their latest model and another evolution of the same formula. While the BA tweeter remains unchanged, the OH1s implemented a new carbon-nanotube dynamic driver and makes all-round upgrades to the design. It has a new 3-part acoustic chamber aiming to reduce reflections, resonances and optimise phase coherence, dubbed SVAS acoustic cavity technology. This comes with a new, sleeker form factor and oval tip design.

The OH1s retails for $199 USD but is available for $139 USD at the time of writing and for the remainder of September 2021. You can read more about it and treat yourself to a unit on ikko.


Disclaimer –

I would like to thank Rebecca from ikko very much for reaching out to set up a review of the OH1s. 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: 10mm CNT dynamic driver, Knowles 33518 BA
• Impedance: 32 Ohms
• Sensitivity: 109 dB
• Frequency Response: 20 Hz – 40 kHz

Unboxing –


I was very impressed by the unboxing experience, it makes the OH1s feel far more expensive than it is. The outer sleeve has specs and anime-inspired artwork, sliding it off reveals an ikko cover that contains the hard box inside. The user is first greeted to a foam plate showcasing the earphones and exploded diagram of their design. A metal ikko pin is also provided in a very CFA-like fashion. Below is another compartment containing a lovely leather carrying case, the cable and selection of ear tips with their own plastic holder. ikko provide a flexible 5 sizes of memory foam and 5 sizes of silicone tips. Of note, the OH1s is now using proprietary oval tips similar to those seen on the Beyerdynamic Xelento. This gives them an especially comfortable and shallow fit, but also means third party tips don’t seal as well on the nozzle.

Design –

Premium build quality has always been a focus for ikko and the OH1s exemplifies this with its unique and visually distinct 3-piece construction. The alloy sound tube construction and signature rippled faceplates sandwich transparent acrylic, giving it a sleek, modern aesthetic with elegant flowing lines. The faceplates especially captivate with rich contrast and dimension, wrapping around the edges of the shell. This is a very attractive and well-constructed earphone that feels solid yet compact and ergonomic. The triangular profile adds further visual intrigue, true to ikko’s marketing they do indeed resemble gemstones in a charming fashion.


The cable attaches via regular MMCX connectors and there is no key system here making third party cable swaps simple. The stock cable is of pleasing construction and complements the earphones themselves well with its lightweight design and streamlined internal braided structure. However, it is a little springy with some memory meaning it can take some time to straighten out when initially removed from the box. Otherwise, there is little to complain about, the smoke jacket is smoother and the trifecta of conductors below give it a unique look. Metal connectors provide a premium look while well-moulded albeit strangely long ear guides aid a comfortable and stable fit.


Fit & Isolation –

If you have small ears and want a super compact earphone with a slim profile, there aren’t many better options than this. The OH1s sits alongside other outliers like the Xelento with which is shares clear inspiration. This is not a bad thing at all, like that earphone, the shells are absolutely tiny, and their rounded edges prevent hotspots entirely. In addition, they are super slim, meaning you are able to wear these while sleeping with no issue. This is aided by the unique fit style, with oval nozzles and the factory tips designed for them. They have an especially shallow fit but, in return, also wear with basically zero in-ear pressure.


This makes them exceptionally comfortable long-term, and you are quickly able to forget about them. At the same time, their lightweight and low-profile nature combined with an over-eat fit means stability also isn’t a concern. They stay put very well. The downside to all of this is passive noise isolation which is well below average. They block some sound but not much even compared to vented single-DD competitors. The open feel is something some may prefer but it does mean you will need to turn up the volume is used during daily commute. They also aren’t really viable for use in especially loud environments even using the included foam tips.

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. 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 OH1s 100hrs of burn-in to ensure maximum performance prior to subjective breakdown.


Tonality –

The OH1s is an intriguing earphone indeed, being surprisingly faithful to reference curves in some regards whilst wildly deviating in others. The net result is an articulate, airy and altogether clearly coloured presentation but also one that remains naturally voiced and tonally clean. It is brighter leaning with an inverse L signature; moderately biased towards treble and, to a lesser extent, vocals. While bass is laid-back by comparison, it is warm and well-structured with a small mid-bass focus, retaining body and power. The new driver and housing design brings a well-controlled sound with some interesting note characteristics throughout. The OH1s feels like an authentic and thought-out design albeit isn’t the most versatile as a result of its colouration. While this means it won’t appeal to everyone, I feel the company has been able to achieve an articulate, vocal-forward sound without fewer drawbacks affecting many competitors.


Bass –

Ikko has combined a warm, full tuning and overall laid-back positioning to provide a solid foundation whilst upholding tonal cleanliness in the midrange. This means that though bass doesn’t announce its presence, plenty of warmth remains to be enjoyed. Its tuning is somewhat atypical with emphasis sustaining quite linearly through the mid and upper-bass but with roll off towards the sub-bass. This is not to be mistaken for a lack of extension as the CNT dynamic driver provides plenty of pressure and slam, albeit I did find this could be overshadowed by the mid-bass on some tracks due to the moderately laid-back positioning. It goes without saying that the OH1s retains plenty of punch and impact in addition to a good amount of gusto and power. As the emphasis is wideband in nature, the timbre is sound, notes are simply slightly thicker and fuller, imbued with a medium but not excessive warmth. Its notes are structured with an emphasis on higher weight rather than plumpness or rounding in the mid-bass as the tuning may initially suggest to some.

This works in tandem with the driver characteristics. The OH1s has relatively slow decay, reinforcing its thick note presentation, and the sub-bass roll off does make some sense here as it aids separation in the mid-bass. I didn’t hear any smear or muddiness however, due to the sub-bass roll off, it doesn’t have the most assertive slam or rumble that has become popularised as of late. Nonetheless, its structured nature and slower decay give it large amounts of texture and the impression of greater dynamics despite attack not being especially aggressive. This reminds me in part of the Moondrop Starfield which shared its CNT diaphragm construction. However, as the driver control is clearly better here, a great performer in-class, the OH1s comes across as more coloured rather than sloppy, upholding strong note definition. It’s a unique bass presentation with a primary focus on note weight and texture whilst still managing to be impressively articulate due to its higher control. This means the OH1s is surprisingly adept at reproducing bass heavy genres such as hip-hop but equally flatters more responsive genres such as pop, funk and jazz.


Mids –

The midrange sits in front of the bass and has a very intriguing mix of qualities. Whilst I was initially inclined to call this a revealing monitor, that isn’t exactly the case. It is, however, well resolved for such an economical earphone, an impression aided by its forward nature. As the OH1s peaks earlier than most at 2kHz and sustains emphasis through to 3 kHz, vocals are brought forward and are increased in size relative to instruments and bass. With a neutral lower-midrange positioning and just ample bass quantity, note weight lies on the leaner side. However, the lift in vocal size works in tandem with a hint of euphonic warmth stemming from the upper-bass to grant a sense of robustness that prevents it from skewing overly lean, metallic or strained. The tuning is pretty solid here and the voicing is natural despite the abundant colouration surrounding. Vocals possess ample coherence and structure on most tracks. A noticeable fall off a 4kHz also helps to counteract the lift in treble brightness and forwardness, meaning it is a low-intensity sound despite being clear and vocal-forward.


I would characterise it more as a vocal-forward monitor here rather than a bright, revealing or clarity-focusing one. This is a great approach as you get intimate, large and well-textured vocals with minimal tonal colouration yet also a good sense of weight when needed. At the same time, extension is maintained via its articulate lower-treble, with a small peak at 5kHz. Accordingly, note definition is lifted and small details are brought to the fore, delivering above average in-class resolving power. However, so too does a little sharpness creep in albeit not to the extent of sibilance. It does give vocals a somewhat breathy and esoteric presentation rather than a full, organic or dense one as the upper-mid nadir might suggest. I did find this to define its voicing more than leanness or dyness in the lower midrange. However, on some pop tracks with heavy vocal processing, I did find this could give the monitor a rather unforgiving character. Altogether, the OH1s is great for those wanting clear, forward vocals executed in a tasteful way and without excessive intensity.


Foreword –

Do note that though my measurement showcases a large 8k peak, this region is emphasized by coupler resonance and may not necessarily be audible. In addition, this region is fit-depth specific, I found I was hearing more brightness around the 10kHz region that was lower in intensity than the lower-treble, which is to my preference. Adjust the tips and fit depth accordingly. Depending on your preferences and ear anatomy, the top-end will either sit at the front of the presentation or just in front of the midrange – greater treble variability is an unfortunate repercussion of such a shallow fit depth. I say this because I’ve seen a range of impressions on the OH1s, some find it neutral, some find it fatiguing. Either way, I would posit that the majority won’t find the enhancements here to be overdone, though do note this isn’t remotely a smooth monitor especially when combined with the slightly laid-back bass and forward midrange.


Highs –

The voicing of the top-end showcases a vibrant, airy performance that avoids fatigue and intensity due to its relative lack of sharpness in the audible range combined with a lift in overtones. Emphasis lies chiefly at 5kHz, instigating a crisp foreground and drawing slightly more focus to the leading edge of notes. However, transient response is on the softer side, leading to an airy and free flowing over hyper-defined or focused foreground detail presentation. The 6kHz nadir could contribute to this impression as well. Instruments sound slightly thin, and notes have a delicate presentation. However, notes decay nicely, imbuing impressive shimmer and vibrance. Still, I didn’t find the OH1s to have the best fine detail retrieval nor the best texture or realistic instrument timbre, it is defined more by the atmosphere it creates in the overall image, rather than the minutiae it discerns within the treble itself.

Above, my ears were hearing level emphasis through the 8-10kHz range sitting just behind the lower-treble. This contributes to an airy, open and atmospheric sound; one that retains good but not outstanding focus on the foreground. Still, I found the balance ample to provide a stable image and, at the same time, weave a convincing sense of headroom. Background detail retrieval is above average but nothing exceptional. The driver does start to break up in this region, so you don’t get an immaculate background or sparkly top-octave. It contributes more to a pleasing sense of air, dimension and layers rather than notable audible detail. The airy and open voicing contributes to the impression of an extended treble despite relatively low resolving power in these regions. It works to the benefit of detail presentation over retrieval and accordingly, small details are brought to the listener’s attention without introducing glare or excessive brightness.


Soundstage –

The OH1s provides a moderately intimate stage but with strong separation/smaller note size that means it still feels relatively open. I has an atypical bias towards height, being more intimate in terms of depth and width but well-proportioned between them. Imaging is quite sharp, you get a strong centre image and a nice lateral spread. Directional cues aren’t super sharp nor is localisation. In tune with the treble note presentation, the overall image too is floatier with less stable positioning. While it lacks the speed to attain holography, the image is fairly multi-dimensional, just not especially sharp. The same goes for layers, there isn’t huge separation between background and foreground due to the airy nature, but the OH1s does have a better resolved background than many around this asking price. Separation is the main strength on display. You get a nice foundation in the bass that remains very well separated from the mids at all times. Note size lies on the leaner size throughout so each note is surrounded by a pleasing sense of air and space.


Driveability –


With a moderate 32-ohm impedance and a higher 109dB sensitivity, the OH1s is relatively efficient and also shouldn’t be exceedingly source sensitive. However, in subjective testing I was surprised at how well this IEM scaled with better amplifier sections especially.

Output impedance sensitivity

Going by the rule of eighths, you would ideally want to pair the OH1s with a source with a sub 4-ohm output impedance. Empirically, I tested this by switching between the Shanling M2X (1-ohm) and Hiby R6 (10-ohms) which revealed a surprisingly similar listening experience. The changes were in tune with individual source colouration though I would posit some of this is also impedance coming into play. The R6 sounded a little tubbier in the bass with a softer note presentation. Treble was thinner but similarly positioned as on the M2X. As a result, I wouldn’t concern too much about output impedance here as the changes are quite small even in sub-ideal circumstances. Of course, a lower number is more ideal.

Driving Power

The OH1s definitely benefits from a dedicated source in this regard, for though the tonality was balanced and volume levels were fine from my Xperia 5 II, I did find the bass performance lacking. In this regard, you don’t need to go overkill, even a dongle like the PEE51 or Hiby FC3 will do just fine. But surely having some sort of dedicated source helps to round out the bass. Swithcing to the FC3 for instance, yielded a noticeably more defined and controlled bass alongside better extension and slam. Stepping up to my desktop stack revealed a larger, airier soundstage. Unfortunately, due to the sensitive BA tweeter, the OH1s does pick up more hiss than most IEMs despite not being especially efficient overall. I was hearing faint hiss on the M2X, but this wasn’t an issue when music was playing. Low volume listeners will want to use a source with a quiet/black noise floor.

Suggested Pair Ups

The OH1s doesn’t require an especially low output impedance but benefits from a dedicated source with regards to driving power and noise levels. Tonally, it pairs well with most source, though those with any form of treble brightness should best be avoided. A warmer or more dynamics source such as the M2X/THX789 are great pairings for bass performance, it definitely benefits from a more aggressive note attack. This applies equally so to the treble due to its softer attack however, again, brightness should be avoided.

Comparisons –


Fiio FH3 ($149): The FH3 is a personal favourite around this price and assumes a similar hybrid driver setup. The FH3 is a bit more balanced, it has more bass and less treble. Its bass emphasis is tonally cleaner and more dynamic, more focused in the sub-bass. In turn, it has a thicker, weightier note presentation with thicker rumble and more powerful slam. The OH1s is slightly more articulate and textured in the mid-bass, it also has slightly higher note definition. But it lacks dynamics by comparison, preferring a smoother textured, warmer presentation. The midrange is more neutral on the FH3, sligthly lean but mostly innocuous. It’s a clean, natural tuning that leaves little to be desired.

The OH1s is more vocal-forward, equally lean but more articulate so it is slightly more vibrant and defined but also less coherent. Otherwise, it sounds similar in terms of voicing and both resolve similarly, the OH1s perhaps a little better. The OH1s has a brighter treble tuning, but the FH3 has a more focused detail presentation with sharper foreground note attack. It has better fine detail retrieval and also isn’t as peaky, delivering better note body and texture. The FH3 has a darker, cleaner background while the OH1s is crisper and more energetic with greater air and headroom. The FH3 has a slightly larger soundstage, neither excel here. The FH3 does have better layering while the OH1s has slightly better separation.

Final Audio A4000 ($160): The A4000 takes the bright tuning approach one step further but with greater sub-bass presence balancing it out. The OH1s has slightly better sub-bass extension but less slam and weight here. The OH1s has slightly better driver control and a slightly more textured mid-bass. The A4000 is more dynamics and punchier, it has a cleaner mid-bass tuning. The A4000 has a thinner, cooler midrange with greater upper-mid bias. The OH1s is slightly more balanced here and more structured due to its lower emphasis and greater density.

I find the OH1s to be more naturally voiced, it doesn’t have as much intensity and glare, and better coherence overall. The OH1s is also more resolving here of layers and small details. The A4000 has a brighter, crisper tuning in the foreground. It has a sharper attack and produces similar detail retrieval to the OH1s at a lower price. Its dynamics driver gives it a bit more texture too. The OH1s is more refined sounding, it isn’t as bright and has a better resolved background with more air and openness, the A4000 sounding more aggressive. The A4000 has a wider soundstage while the OH1s has better imaging and layering.

Campfire Audio Satsuma ($199): The Satuma is a single-BA earphone with a vocal-focus making it direct competition to the OH1s. It has a fuller bass with greater sub-bass weight but also far less extension compared to the hybrid OH1s. It lacks pressure and power at the very bottom despite being more forward here in tuning. The OH1s has a more textured, powerful bass response despite having a bit less sub-bass presence. The Satsuma is faster decaying and a bit more articulate but doesn’t have the same natural timbre to my ears. The midrange is slightly more forward on the OH1s, the Satsuma has a smaller vocal size and isn’t quite as intimate. It has a warmer voicing and a smoother articulation giving it higher coherence.

The OH1s is more vivid and immedaite. It is more textured and resolving, with greater vocal size, it sounds more powerful and structured. The Satsuma has a smoother lower-treble but some crispness and air in the middle-treble. While it does have a sharper note attack than the OH1s, its smoother tuning means it is slightly less detailed in practice. The OH1s has a bit more background detail, the Satsuma is similar in its airy approach but less resolving here. The Satsuma has a wider stage despite this, and a darker, cleaner background. It has sharper imaging too while the OH1s has better separation.

Moondrop Blessing 2 ($319): Moondrop doesn’t really have a direct competitor in this price range, I suppose the new KATO is closest but that model wasn’t available to me at the time of writing this review. The question then becomes whether buyers should consider saving another $100 and I think a reasonable case can be made.

The Blessing 2 is equally well extended but has a heftier sub-bass presence. It has more slam and weight. The OH1s is slightly more laid-back and has a less prominent rumble. It is slightly fuller and warmer and also showcases slightly better driver control and note definition, the B2 being more dynamic and linear in return. The OH1s has a slightly more vocal-forward midrange but not by much. The voicing is also not too dissimilar, the OH1s is a touch leaner and has a sharper articulation, but it’s also a little more separated. The B2 is more coherent with more accurate note body. It is more resolving, it has better extension and layering and also a more consistent voicing on tracks of different mastering styles due to its more linear tuning.

The treble plays into this mostly, the B2 is more even throughout, the OH1s has a bumpier tuning. The B2 has a sharper note attack in the lower-treble. Its notes have more bite and it has much better fine detail retrieval, a more focused detail presentation and a cleaner background. The OH1s is brighter, it has a thinner note body but also higher clarity. Chiefly, it is airier in the middle-treble, albeit the B2 is noticeably more resolving of detail here and less polarising in terms of brightness. The B2 has a larger stage in all dimensions but most will appreciate its much sharper imaging. the OH1s has slightly better separation.


Verdict –


The OH1s is a beautifully designed earphone with excellent build quality and a super svelte form factor. The sound has a unique character that will no doubt appeal to some but cannot be universally praised and recommended. I was impressed by its controlled and textured bass and airy treble. Similarly, it has a large, well-resolved yet low-intensity midrange vocal lovers will enjoy. Conversely, this is a somewhat unfocused sound altogether; pressure and power in the sub-bass leaves wanting as does note attack, imaging lacks stability and assertive directional cues in turn. Furthermore, its especially fit dependent middle-treble and lean note body mean it isn’t the most forgiving listen either.

Accordingly, while the OH1s attempts to be an all-rounder and perhaps abstractly address fallibilities of a bright/revealing signature, it ultimately lacks clear direction and falls short on genre versatility too. It isn’t an earphone with many huge flaws to criticise but certainly idiosyncrasies one should consider before purchase. If my comments don’t sound like deal breakers to you, then there is much to enjoy beyond this. Expect industry-leading comfort and compactness, a resolving midrange and airy top-end that surely carve its own clear niche in-class.

The OH1s can be purchased from ikko for $199 USD and a promotional price of $139 USD during September 2021. I am not affiliated with ikko and receive no earnings from purchases through these links.

Thanks for reading! If you enjoyed my review, please see my website for more just like it!

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

Introduction

Ikko again insists on keeping the OH1 series and adds an "s" to one of its first models, but at twice the price. The profile is quite different. It keeps the characteristic dented outer face, but adopts many new technologies, such as the so-called SVAS (separating vector acoustics system). It continues to use 1 x 10mm DD, with deposited nano carbon diaphragm + 1 x Knowles 33518 BA. The result is an impedance of 32Ω. The body is composed of several parts, made of resin and aviation grade aluminium alloy, to generate a pure and transparent sound, while reducing the weight of the headphones. The sound output of the headphones is oval, the OH1s are more ergonomically designed and improve wearing comfort. The OH1S uses a special resin material for effective sound damping. With Ikko tips, the physical noise reduction is greater. The cable has also been improved and consists of 127μm of high-purity monocrystalline copper, with a silver-plated magnetic core. The package still looks luxurious and with a good and particular collection of Ikko's own tips.
In this review we will see how these new features influence the sound of the OH1s.



Disclaimer

Penon Audio Store, offered me this model, in exchange for writing an honest review. I want to make it clear that all my opinions written in this review have not been conditioned by this fact, nor will I ever write anything that I do not really think or feel here. I will only write about my personal opinion in relation to the revised product.



Specifications

• Driver Type: 1 DD 1omm with nano carbon deposited diaphragm + 1 BA from Knowles 33518.
• Frequency Response: 20Hz-40kHz
• Sensitivity: 109dB/mW
• Impedance: 32Ω
• Jack Connector: 3.5m SE straight.
• Capsule Connection Type: MMCX.
• Cable length: 1.2m.

Packaging

The Ikko Gems (this is the name on the box) come in a classic box decorated with an anime girl on the main side. Its dimensions are 202x138x48mm. On the back side are the specifications (in Chinese and English), as well as a picture of the capsule exploded view. In reality, what is described is a cardboard box that wraps around the package and can be removed from the side. Once this operation is done, another decorated cardboard wrapper appears. The front side has a realistic photo of the capsules and the back side is the same as the first wrapper. This second wrapper is removed by resting the box on its lower profile and sliding it upwards. In this way, another chest-style box is exposed. It is completely black, with a fine mesh weave. In the upper right corner is the Ikko logo, in gold lettering, and in the lower middle edge, a yellow painted box, which helps to open the lid. Underneath are the capsules inserted in a thick block of foam, which has a black cardboard with hollow white drawings describing the product's exploded view. There is also the classic cufflink with the Ikko logo. After lifting this block, there is another level protected by a black cardboard separator, which holds a leather pouch, a box containing the cable and a blister with the silicone and foam tips.
The complete contents are as follows:

• OH1s capsules.
• 6 pairs of specially designed Ikko silicone tips in different sizes.
• 3 pairs of Ikko i-Planet foam tips.
• 1 MMCX cable.
• 1 clear brown leather bag.
• 1 pair of tweezers to remove the filters from the capsule mouthpieces (inside the leather bag).
• 2 filters for the capsule mouthpieces (inside the leather bag).

Ikko is characterised by attractive and visible packaging, although I find the flat leather bag a bit inappropriate. The tips are of Ikko's own design, but their final result and impact on the sound is not the best for my taste.



Construction and Design

The capsule design has a shape reminiscent of their previous models. This time, however, the capsule is made up of three layers. The outer layer is Ikko's characteristic dented metal face. There is a central part made of almost transparent resin, which is a unique structure responsible for sound diffusion. The inner side is also made of resin, but black. The capsule is oval and allows the use of special tips. These tips are unusual, although their shape is somewhat dubious, not because of the comfort, but because of the sound offered in the end. Ikko's own i-Planet foam tips are also included.
The capsule design allows for a smaller size and a clear lighter weight. This is perhaps the highlight of this section. The cable connection has been changed from 2Pin to MMCX. In my opinion, this seems to be a step backwards in design. There are two holes in the capsules, one in the centre of the inner side and one on the edge of the outer side. The mouthpieces are oval and are protected by a resin filter with visible holes. The Ikko logo and a very small letter indicating the channel is written on the outside of the inner side.
At the end, the capsules have 4 separate elements, outer side (aluminium), middle side (resin), inner side (resin) and filter. The divisions can be seen at a glance and the internal design seems quite complex, due to this superior number of parts. The oval shape of the mouthpiece is quite debatable, both for ergonomic and fitting issues, as well as for tip fit issues.
The cable is thinner than you might expect and is two strands composed of 127μm wires of high-purity monocrystalline copper, with a silver-plated magnetic core. As mentioned, the connection is now MMCX and these connectors are protected by black plastic sleeves with the channel lettering inscribed on them. They have a soft angled shape and the cable coming out of them is protected by a semi-rigid black plastic sheath. The cable cover is transparent and reveals blue and red-tinted strands. Both the pin, the splitter piece and the 3.5mm gold-plated connector sleeve are polished and shiny metal cylinders. The Ikko logo is engraved on the jack connector. There is no choice of balanced connection, which is a negative point for a model of this price, when such a connection is becoming increasingly popular. The cable, despite its bombastic description, doesn't look like much and is very susceptible to being swapped for a balanced cable.
The design is innovative, building on a familiar base. The size is smaller and the weight, too, are the strong points in this section. The cable and the oval mouthpiece is a more debatable design.



Adjustment and Ergonomics

There are two things that improve the ergonomics compared to the OH1 and, above all, the heavy OH10: one is the smaller size and the other is the lower weight. On the downside is the length of the mouthpiece, which is still a bit short, and another negative point is its oval shape. The use of the standard tips doesn't help me to find a setting that allows me to extract the potential of this new model. I have tried all the standard silicone tips and none of them offers the best version. The bass escapes very easily and I don't think that's the real sound, especially not coming from Ikko. So I had to resort to other tips from my collection. In the end, the recurrent big tips with foam filling, homemade, have hit the nail on the head. The internal channel of these allows the oval mouthpiece to fit, they fix the capsules in the bell and extract the best bass they can give, without losing any of the clarity they treasure.
It is clear that despite the effort made by Ikko, the standard tips, the short and oval channel, are not going to be the best solution, neither in terms of fit, nor in terms of final sound. And I find that this can be a problem, because the sound may even sound worse than it really is.



Sound

Profile

The profile is balanced/neutral, but with a slightly bright mid-centric tendency. The bass is relatively linear, with a weaker sub-bass. The high mids are emphasised, but without sounding sharply clear. The treble is controlled in its initial part with a flash of brilliance before 10khz.



Bass

It makes no sense to discuss Ikko's good work in the low frequency range, given the models they have in their catalogue, such as the OH1 and, especially, the OH10. However, the lower range of the OH1s is far from those IEMS, if we talk about net presence within the overall sound. It is clear that the tuning of the current model is much softer and lighter, taking a back seat to the other ranges. Getting the good tuning that my home hybrid tips provide, the bass feels well represented in the music, but it is never predominant, but a permissive base that offers texture and body to the sound. Bass-lovers will be disappointed if it's power they're after, but audiophiles will be very pleased with the level the OH1s are at. Personally, I would have liked a few dB more around 20Hz, keeping the same level in the mid-bass and thus gaining more depth, offering a more physical and sensory base. This is not the case and what is noticeable is a clean mid-bass, without a hint of rubberiness or sluggishness. The decay is quick, there is no aftertaste, no contamination. With this, the respect that the bass has over the rest of the ranges is very high, especially over the upper mids and first treble, whose presence is superior. In a certain way, the colour and sonority of the bass can be a tasty treat, something that can incite us to raise the volume to appreciate them more closely. But the idea is not a good one, because the upper notes will always sound more present, which can be a bit disappointing if you don't like the neutrality of this low end. That's why one has to be satisfied with the good texture offered, its descriptive capacity, the remarkable resolution and precision, even the eloquent, if subtle, recreation of planes.



Mids

The mid-centric tendency of the OH1s is not of an absolute nature. The cleanness of the mids facilitates the presence of the lower midrange and the emphasis on the upper mids finishes the job. The representation is less analytical than I expected and the connection with warm sources tones down the excitement in the upper part of this range, giving it a somewhat more analogue and rounder feel. On the other hand, the pairing with cooler sources doesn't turn the set into an operating room, but it does bring in an amount of air and space that the OH1s benefit from. And in this respect, the new Ikko is average. Don't get me wrong, the sound is not congested, but it is not characterised by a very open or expansive feel. Although it is true that the fine tuning of its BA is capable of providing a lot of detail, backed up by its bright tuning. The biggest beneficiary of all this is the timbre of the mid-range, which is enriched by the sum of the above-mentioned consequences, including the low end and the particular tuning of the treble. This is perceived in compositions with few instruments and voices, where they have a special sonority, although natural, with a lot of texture, great definition and descriptive capacity, which gives them a facility to express nuances in a fluid and extremely effective, even easy, way. The sibilances are controlled in a sweet spot, where that characteristic flare appears and stops, ending in a rounded and smooth way, almost as if this peak were drowned in the void, but not the rest of its journey.
Sometimes, the instruments don't feel as expressive or eloquent as the vocals, maybe it's because of that more limited scene, that more intimate character that prevents a wider range for them. Although for dense, even oppressive styles, metal, hard rock, with many layers of guitars, drums and cymbals, the OH1s do very well, because they are able to generate a great wall of sound. But at the same time, they are very adept at discerning between all the elements excellently, thanks to their high resolution and level of definition. Really, they are highly recommended for these styles because the good timbre I talked about before, enhances the sound of the guitars and the drums have enough body to integrate perfectly in the recreation of the image. Without a doubt, this is a great discovery in this sense.



Treble

As I implied above, the treble has a particular tuning, full of highs and lows. They start slightly depressed and thereafter alternate more or less prominent peaks and valleys. The result is that the flashes are not homogeneous. The tuning tries to bring clarity with the thrust of the mid-highs, and then offers control by suppressing the treble in the first phase. This is good for the sibilance, but loses coherence at other points. Even more so, when there is a powerful flash, to end with a valley, quite marked, that cuts the sensation of air. It is not really a homogeneous treble, although I don't think that this tuning is the result of chance. I think Ikko has been looking for something, but I can't find what. There is clarity and transparency, very good definition and detail, resolving power and descriptiveness, as I have already mentioned throughout the review. But the sense of space, distance, separation, air, openness and expansion is more limited. Perhaps they have tried to favour the midrange, rather than show a purer and freer treble, something that also seems to have been done with the low end. In this way, the bands at the extremes seem more like complements to the mid-range, rather than areas for individual showcasing. This partial sacrifice, in my opinion, is not entirely well executed. The lack of air limits further development of the sound, also of its scene and, after all, of musical freedom. If I may use an ambient comparison, the treble of the Ikko OH1s is like a clear, cloudy day.



Soundstage, Separation

And with everything described so far, this section has become quite clear, even before developing it specifically. To come to the point, the scene does not look very big, there is a clear sensation of width, even height, but the perception of depth is not so pronounced. The three-dimensional recreation is average, there is no holographic representation, no large spaces between elements. There is separation, but not a dark or pronounced void. And while the definition and resolution are more than remarkable, the sound doesn't quite expand due to lack of air. The result is a good scene, albeit a low B-plus. However, while all this might be in clear opposition, the descriptive level, the recreation of detail and nuance goes beyond the mere emphasis of some key areas of the frequency response. Texture, as well as small elements, are shown with a surprising ease. And in the end, good technicalities are not the result of artifice, but of good components and a job well done in this sense. Without a doubt, this technical section is another of the strong and distinctive points of the OH1s, as you would expect from Ikko.



Comparisons

NF Audio NM2+

As if it were a more extreme version of the present Ikko OH1s, there are the NF Audio NM2+. And they are more extreme because their tuning in the upper midrange and treble point proves it. The NM2+ are risky, so much so, that they make the OH1s soft and warm. But starting with the low end, the NM2+s present a slightly but noticeably greater power in this range, as they have a more energetic and deeper punch, with a higher and more sensory sub-bass, capable of filling the bass body and generating a fuller and more vigorous feel. It even seems that the low end of the NF Audio is more accurate, enjoying slightly more speed as well as punch. The Ikko's are lighter in this range and offer very well-defined, high-resolution LFOs, but the less accentuated sub-bass detracts from the overall power.
In the mid-range, as I say, the NM2+s make the OH1s warm and soft. The NF Audio are much brighter, but their edges are also much sharper. These sharp edges are a double-edged sword. It is clear that their expression is more analytical, but also more risky, becoming more penetrating. Compared to the Ikko, they might even be irritating. But the amount of information they manage to extract compared to the OH1s is superior, exposing it much more clearly and in the foreground. Their problem is that this overexposure is dangerous; sensitive ears may prefer a softer, more controlled presentation, such as that offered by the Ikko. They may not be as revealing, but they are much safer. The exposure of details is not so much in view, but they have a good definition, even a remarkable analytical level, which allows you to see the smallest nuances, even if you need to pay more attention. On the other hand, the NM2+ draw the voices on a close and superior plane, especially the female voices. The Ikko's blend these more with the music, giving them a softer, less bright tone and a comparatively more reserved representation. The instrumentation of the NF Audio is also clear, both in its edges and nuances, as well as its body, although the tone and timbre is brighter. The Ikko's are more honeyed, more muted by comparison, but also more polite. In the upper range, the NM2+ hold nothing back and start strong, almost diametrically opposed to the Ikko. It is in the upper mids and in the first treble that the differences between the two models are most significant. But this difference is such that it polarises the sound of the two IEMS and makes them play differently. It is clear that the bass also has an influence, but less than the treble, because a higher amount of air is also perceived in the NF Audio. This adds more separation, distance, even dynamics, gaining a darker background, which is more easily perceived. The sound of the Ikko's is more cohesive and lacks the freshness that the greater amount of air brings. Thus, the soundstage is bigger, deeper and rounder on the NM2+, while the OH1s offer a flatter representation.
If someone is looking for a smoother, warmer and more secure tuning than the NM2+, while maintaining a relatively mid-centric profile, the OH1s could be a good alternative. But if you're looking for a more explicit and vigorous sound, you'll go for the NM2+s, as long as they are clear about their more treble-oriented profile.



Conclusion

Ikko is once again releasing a new model in its OH series and continues to rely on the Knowles 33518 BA driver, together with a new 10mm dynamic driver. But the real revolution lies in the design of its new internal cavity, which adopts SVAS technology. The new three-part capsule and the new oval mouthpiece are no slouch either. The result is a smaller and lighter capsule. To top it all off, the OH1s come with Ikko I-Planet foam tips and specially shaped silicone tips.
In terms of sound, the OH1s move away from the profile of the previous OHs, seeking a better balance between the three bands. The result is a sound whose midrange is enriched by the treble and bass, at the expense of reducing the prominence of these side bands. This is not a purely mid-centric IEM, but it is a more neutral alternative to its bass-heavy OH-series siblings. This makes the OH1s a more refined and, why not say it, audiophile sound signature.



Sources Used During the Analysis

• ACMEE MF02s.
• Zishan Z4.
• Tempotec Sonata E44.
• Hidizs S9 Pro.
• Earmen Sparrow.
• S.M.S.L Sanskrit 10th MKII + iFi ZEN CAN.

Ratings

• Construction and Design: 83
• Adjustment/Ergonomics: 84
• Accessories: 80
• Bass: 75
• Mids: 89
• Treble: 72
• Separation: 80
• Soundstage: 78
• Quality/Price: 80

Purchase Link

https://penonaudio.com/ikko-oh1s.html



You can read the full review in Spanish here:

https://hiendportable.com/2021/09/04/ikko-oh1s-review/

Ikko OH1S

Ikko is a brand that I have been aware of but never had the chance to hear one of their earphones until I was reached out from the group to do a review for their new OH1S. Several months ago I was browsing around Amazon and I remember a few of the cable enthusiasts friends on headfi was recommending the Ikko CTU-01 cables as a very solid cable for the price so I went for it and so it did turn out to be a very nice cable and so my curiosity grew as far as wanting to evaluate how they tune and as chance would have it, soon after that purchase I got contacted by the group to check out their new OH1S.

I would like to thank Rebecca of IKKO for the review sample, you can find out more about the OH1s on their official page here. I have burned in the OH1S for a weeks time and for sound evaluation I will be using my Fiio M15, Shanling M6pro, M5s, M3s, IBasso DX160, Pioneer XDP-30r, IBasso PB3 and IFI Black Label for amping. These are my thoughts about their newest earphones, the OH1S.

Their OH1S comes in a slick package and is one that uses high end production values as far as design goes. I notice a trend nowadays to use anime characters in marketing for earphones and Ikko here is following suit with a nice hand drawn female character light on her feet obviously enjoying some Ikko earphones on the box that might appease the younger set in aesthetics.

The OH1S is unique in several ways. It has a unique half metal and half resin ergonomic smaller shell design for comfort and durability. Its smaller triangular shape certainly looks dense with a rock solid feel. The back end of the shell has a textured look and feel that is again unique. This combination of a central resin infusion with the metal makes them look modern with an artistic flare and has grown on me as far as looks goes.

Another aspect of the design that is unique is that the OH1S has an oval shaped nozzle not something you see too much in the industry. So the tips that are included were made for this oval shaped nozzle. The included foam tips are a donut shaped rebound type foams with a medium sized opening that sit shallow on the tip of the nozzle giving me the best comfort, passive isolation and sound. On a side note. You will not be able to use the included silicone set or the foam tips on other earphones. They were specifically designed for the oval nozzle design of the OH1s.

Unfortunately the oval shaped silicone tips that were included will be a hit or miss depending on your inner ear shape. They work well enough for me but I noticed one part of the tips end up losing seal in my ears so it was not the best for me. The good news there is that you can use your aftermarket tips which work fine on the oval nozzles. In rounding out the accessories you get a pocket pouch and an extra set of front nozzle grills just in case you need to replace those.

The included cable is a thinner high purity silver plated crystal copper cable that seems to transmit a very clean pure sound to the OH1S. Ironically seems to be a thinner version of their CTU-01 cables I bought before getting the OH1S sample. I can tell since the CTU-01 has the same exact strands and coloring of the included cables but using much less material.

Fans of thinner/ skinny cables will like the included cables but I do notice the cable is more stiffer than I would have liked, taking on some springy characteristics and not nearly as pliable as it should be, especially coming from a thinner cable.

These cables also incorporate a unique look to go along with the OH1S theme of uniqueness. The thinner braided wires incorporate red blue and silver colored cores using a grey clear PVC type covering. Minus the minor stiffness the cables are certainly a higher grade of cable included vs your standard throw in cables as you're essentially getting a customized thinner version of their highly regarded CTU-01 cables.

So I am a cable guy meaning I do cable reviews and started two very active cable threads on head fi. I don’t claim to be a cable expert or anything like that but I do know my cable matchups and how your earphone cables affect a sound presentation. If you're not a cable believer than what I mention here you can skip but for folks that notice some cables match better with a given sound design over others this little advice is for you.

I have to admit as resolving as their included cables are. It is not the best matchup for the sound tuning on the OH1S. Ikko is certainly not the only manufacturer that is guilty of throwing in a highly resoliving cable for a highly detailed sound design on an earphone. This is just my opinion of course but Ikko would have done better throwing in a thicker copper cable instead, will let you know why a bit later on in the read.

Ikko uses a unique inner housing cavity structure called SVAS or Separating Vector Acoustics System which is touted as enhancing volume, reflection and diffusion angles for maximum optimized sound output from the limited space of the inner housing. A fancy way of saying their drivers was optimally positioned or there could be something to this design either way the sound presentation is highly detailed in nature which goes along with how they were tuned as well.

This detailed nature and clarity is a standout of the OH1S design but the cable also enhances this clean detailed design. Which in the earphone industry a lot of manufacturers are guilty of trying to enhance with a cable what is a base design that is already very etched for their base tuning. That's great if the sound was not so chiseled and detailed in design but since it is. You get extra chiselness. The cable essentially enhances brightness. As a tester go from your copper cables back to the included one and you will understand what I am saying here.

The OH1S is a U shaped sound signature which incorporates a high level of detail with a sharp if not a chiseled type of imaging for the sound tuning. This could be the result of that SVAS inner cavity design but also incorporating ample upper mid gain and a crisp 8Khz upper treble emphasis. Clarity is the first thing you notice for the sonic reproduction. It has a distinct clear sound tuning. Which can also be described as energetic in nature but also showing some good rangy dynamics at times due to how the sound is projected.

Much like how the overall uniqueness factor of the design is how the sound is projected has a uniqueness as well. Sound is projected with ample width of sound and has some good depth but has almost no height to the sonics. It is like your hearing sound using a wider lens on a camera to see a broader image or in this case to hear your music. It is stretched out side to side with not too much in the way of height for a proper holography or dimensional envelopment but more like a 2D painting on a broad canvas. I am thinking this might have to do a bit with that oval nozzle design but to my ears anyway this is how I hear them.

Treble is for the most part very clean but sees the most emphasized aspect toward upper trebles. I can tell the BA was used for the treble as its tonality and timbre aligned with BA treble. Treble has ample energy and has good sparkle and extension. The treble end of the overall design matches well, and for detail lovers will like the energetic sparkly treble of the OH1S. Treble however is also enhanced on top of being above the mids and bass using their stock cable.

This is the reason I suggest using a copper cable as pure copper cables will not highlight the ample treble emphasis as much, smoothing out this aspect giving a more cohesive and smoother performance for the region. As they are, the tuning for the trebles does stand out a bit and is not as smoothly blended or balanced as much as I would have liked. This one will be more for folks that like energetic treble tunings and love them some treble presence to the sound design. I give credit to the Ikko tuners here as the treble tuning is just below the threshold of edginess and just below becoming overly splashy while clearly showing that it is a treble infused sound signature. The mids on the other hand are a bit laid back in presentation vs their treble forwardness in comparison.

The mids has an upper mids enhanced design with vocals that are highlighted and sounds good for vocal performances. Has plenty of detail for instruments, imaged well for the larger scope pieces that shine with the OH1S. Both the 10mm carbon nano dynamic and the Knowles BA used on the OH1S are higher resolving in nature adding a hyped upper mids and enhanced upper treble tuning giving the OH1S an energetic clean detailed sound signature. Again their included cable enhances these aspects which makes the OH1S lack in the way of natural warmth to the sound presentation.

However, going back to the stage element of the OH1S. It's not the most intimate of sounds but more laid back giving a good even spread of its mids presentation. Music notes lack weight and fullness but makes up for it with that clean side to side imaging and an ample depth presence. Sometimes in sound designs, too much of a good thing might be a bit too much. Hence the OH1S needing more of a smoother warmer cable to offset some of that slightly overly hyped clarity of the OH1S but certainly not to enhance it.

Its bass is the best aspect of the OH1S sound design. The 10mm composite carbon nano dynamic is a highly resolving bass specialist. This was the case for the first ever carbon nanotube earphone I can recall in the JVC FX41 which had to this date one of the best bass designs for a budget level set. I still own them and listen to them on occasion, I have yet to listen to a poorly represented carbon nanotube bass design. Difference in tuning yes but overall stellar performers for bass and this also applies to the Ikko OH1S.

Ikko shows a very good ability to tune the low end for their OH1S. Its bass end is tight and dense with excellent agility/ bounce with very good range. It is like the rest of the tuning, detailed in the presentation. Its bass end has a moderate boost but is defined well for the given price point. I noticed since the overall projection of the sound is laid back for the mids, the bass end has better head room to really show a dynamic range for bass infused tracks. Its tonality is accurate while I would have liked a bit more emphasis for its sub bass emphasis, its bass end shows an addictive tactile quality that bodes well with all music genres I have heard on it.

The OH1S can do bass heavy tracks all the way to light bass with everything in between. It has the most natural tone out of any of the sound aspects on the OH1S and while moderate in emphasis gives one of the cleanest renditions of bass notes for the low end. Its tone is matched well with a highly textured low end. Its sub bass needs just a bit more in the way of decay and or sustain but otherwise folks that love a tiger bass presentation will love how agile, snappy and well defined the OH1S bass is.

Overall. The Ikko OH1s with its clean energetic sound, its laid back presentation with a punchy detailed bass will be enjoyable for folks that crave such designs. It has a good technical foundation but some aspects Ikko can improve upon. It needs more body to the sound. Its thinner note weight will most definitely be an acquired taste. The sound reminds me of one of them long distance runners, never seen an overweight long distance runner is my point.

It presents music a bit thin and that might be something that could be attractive to some and not others, but for music to be more natural sounding in presentation it can’t be overly thick and heavy in note weight and the opposite too thin either. The Ikko OH1S sounds just a smidge on the thinner side of note weight overall.

However the OH1S has a highly precise clean sound signature that some folks will be looking for as a premium to how they like a sound presentation. For me anyways, I need a bit more protein in the mix here. Overall the sound is enjoyable and is engaging regardless especially with the right aftermarket cables, for that I consider the Ikko OH1S a success. I also recommend your more musical full bodied warmer sounding sources for the best source synergy. I look forward to future designs by the Ikko team as they seem to know how to design a well made hybrid. As always, happy listening and thank you for taking the time to read.