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!