Wonderful guitar harmonics due to extra interaction from Sonion BA and 10mm Planar driver Speedy sculpted bass inhabiting its own area in the stage Smallish 6 gram form factor holding ultra smooth fit and finish Great 4.4mm included Flagship 612-core 5N OCC Silver plated cable affair Supreme box opening experience with a ton of goodies Midrange focused with beautiful vocals and anything else that resides there Smooth 10mm Planar treble ideas adding only a hint of Planar character Better note-weight than the TRI i3MK3 reads out on paper Medium-wide stage, offering the majority of size in the large midrange provided Cohesive well beyond what you may expect Added note-weight due to three pairs of Knowles Acoustic Dampers A fun and subtle sound, never being too drastic in any one area
Cons:
Could not be enough bass amount for bassheads, or dramatic music that counts on bass for drama
The KeepHiFi TRI i3MK3 Universal IEM review Redcarmoose July 14th, 2025
Introduction: Normally I review “just out” IEMs. And while the i3 MK3 came out a year ago, the TRI i3MK3 has garnered quite the cult-like following with an ample share of publicity already! I will do my very best here to review it, and hope to maybe add a few ideas to the perspective at hand? All and all we have a slanted neutral IEM demeanor, with Hybrid character personality coming from the 10mm Planar reproducing the highs, a full-on midrange taking the Sonion BA to its formidable limits, and a quick 10mm Beryllium DD for the careful low-end.
The KeepHiFi retail company: Somehow I have only reviewed the KBEAR Lark, way back in February of 2021. It’s not that KBEAR has not been around and noticeable, maybe I just walked between the raindrops here? The truth is KBEAR/KEEPHiFi is a fully substantiated company offering currently 7 different IEM cases, 14 different styles of ear-tips, 40 different cable choices, 9 different DAC/Amps and 98 different IEMs. Now while all their cables showed the KBEAR branding, or TRI branding, the IEM selection also held along with the KBEAR line, many other brands like TRI, CCZ, Tangzu and recently EarAcoustic Audio!
Here we have a Hybrid 10mm treble Planar Driver, a Beryllium 10mm bass DD and a Sonion 2356 BA midrange driver. As such these 3 sound tubes are also fitted with Knowles acoustic dampers. Then the build…….a masterpiece of CNC aluminum. Sure before I got the i3MK3 I knew it was a specially anodized purple creation, and I knew there was some amazing CNC workmanship, only I didn’t realize it would be just this nice? The build quality, fit and finish can’t be overstated enough. I mean sure I see a few new IEMs every month, and this has gone on for a couple of years, yet the i3MK3 is a standout product, both in looks and feel! It really seems like a family heirloom when you hold it? More on the build and design later…………..
All this at $219.00 would be good enough, only the box opening experience is better than I have had for a while. Meaning if the IEM itself is grand, why not include extras inside the box? You get a brush, a nice smaller flip-top case, 11 different pairs of ear-tips, and an amazing 4.4mm cable!
Now sure other IEMs come with stuff close to this, only you can tell a lot of care went into making the TOTL Flagship of the line box opening experience memorable. Plus………..a first in a long, long time, I am using the included ear-tips and cable. If anyone has read my reviews before……….I’m searching for the best aftermarket cables and ear-tips normally about 99% of the time. Only here we are presented with first quality stuff that works, and better than works, it brings the TRI i3MK3 into total focus!
Build: One of a kind maybe. I say this as I have never come across a build like it. Seamless fit and finish, coming from perfect aluminum CNC craftsmanship. Take a look at the fit here in the photos. Notice how the two lower and upper halves join. Notice the nozzle angle and length. Note how the nozzle screen is flush to the top of the nozzle, these are all the things I notice. At only 6 grams each in weight and the smaller side of medium, really actually small is the size here, the i3MK3 can do no wrong as far as fitment goes. Rubbing your fingers along the bevels you come about a smoothness and polish unique in the IEM world. And just like the care taken in the IEM packaging, the build is very carefully done…….at least in my humble opinion? This same easygoingness travels into the frequency response and arrives at your eardrums the same way. Only a single vent remains off to the side, for breathing. Also after such nice results from the ear-tips, I don't feel the need to experiment further. The cable completes the results as not having a too robust of an ear-hook, and the end-results obtained showcase a fitment which never moves or needs adjusting. With so many on the border of needing adjustment, this freedom of placement really becomes of value here! Call me smitten with the I3MK3, but I rate it 10/10 in comfort and economics…………..and I’m sure TRI already knows this, I mean it is apparent they did their homework here. Such a fitment is a big part of the usability and resulting comfortability at hand………resulting in lasting use long into the night. Why doesn't every manufacturer follow these rules? It may be due to the smaller 10mm X 2 drivers and BA applied to the internals, as there is a resulting smaller size here that just plan works.
The above EarAcoustic Audio SPA-Pro MAX shown with Penon PAC LS ear-tips and SIMGOT AUDIO LC7 cable.
Comparisons: Look, at the start I was not sure if the EarAcoustic Audio SPA-Pro MAX would be the perfect battle to go up against here. I received the two IEMs at approximately the same time, and during 6 days of burn-in the two IEMs were all I was really listening to. At $219.00 for the i3MK3 and $219.90 for the SPA-Pro MAX…..they are priced the same.
Then it hit me, maybe this is destiny? Of course they should be compared back-to-back.
Really the two are opposites being the SPA is a 11.4mm full-range DD and the i3MK3 is a 3 driver Hybrid. Also they completely differ in playback. Meaning the SPA comes across thick and beefy, cohesive and more bass laden, where the i3MK3 comes over as more mid centered, and while still providing an exquisite leaner style of careful bass, the SPA emits more lower midrange along with this slight bass slowness that comes from the lumbering of the 11.4mm full-range. One shell (the i3 MK3) is CNC Aluminum at just 6 grams, the SPA is also CNC Aluminum alloy but maybe due to the increased size seems much more heavy (than it is) at 9 grams. Really again the two IEMs are the opposite here, in that the i3MK3 has very little extra shell expansions into universal custom form around your ears, where the SPA-Pro MAX is adding fins and curves to try and occlude the ear and add areas for your ear to hold them in place.
The more I examined the two IEMs the more I started to get excited about a match-up. After spending almost a full-week hearing both, I actually started to view them as complementary IEMs. Meaning one does special things opposite to the other, therefore it would be an option to own both………but let’s now do real side-by-sides……….let the sparks fly!
TRI i3MK3 versus the EarAcoustic Audio SPA-Pro MAX: Here I’m using the SIMGOT AUDIO LC7 modular cable with the SPA so that both IEMs could have a balanced 4.4mm drive. I’m using the Penon PAC LS ear-tips on the SPA and the wide-bore TRI ear-tips on the TRI i3MK3. To get the TRI i3MK3 an advantage I chose the Sony WM1Z DAP. Such a DAP character goes to ultimately enlighten the TRI i3MK3 by providing extra physical oomph to the lows and expand the treble stage even broader due to the fishbowl effect of the 1Z treble staging. In fact this set-up of using the Sony WM1Z I determined to be almost too favorable to the TRI i3MK3, hence deciding to use (also) the WM1A on a different part of the comparisons due to the 1A bringing the SPA into better tonal character-isms. While if you only had the WM1A, you would be more than happy to only use the Sony WM1A for the TRI i3MK3, and the 1A adds the vocals and stage sizing into SPA-Pro MAX playback………only you seem to get the full-big-breakfast with the TRI i3MK3 and WM1Z combo, and I didn’t want to leave that out of this review, how could I?
TRI i3MK3 and the Sony WM1Z: The added physicality seems to provide that extra density to the TRI i3MK3 bass adds.
Meaning sure the TRI i3MK3 bass is nice, only we welcome this added bass presence and separation from a separate full 10mm Beryllium DD. Such a bass holds a more refined example sitting slightly farther back in the mix than the SPA-Pro MAX and going about its day with slightly more sculpturing and definition. Where the SPA-Pro MAX has a warmer and more accessible bass………….that seems to cut through offering a more forward presence in the stage. Not to mention the SPA-Pro MAX is way more efficient taking less power to reach the same volume levels. In many ways I like the clearer idea of the SPA-Pro MAX playback, that sure the stage may even be bigger to the SPA, I don’t know, they are equals here as far as stage goes, with each IEM providing its own set of favorite frequencies to spread out the stage.
Though I do know now why there is a guitar player on the box-opening experience here.
Even with the V shaped Sony WM1Z tonal personality, the guitar harmonics are fully more filled-out and colorful to the TRI i3MK3. For that matter using the Sony WM1Z resulted in more midrange push to the TRI i3MK3 and a rewarding sense of clarity there. Still the SPA-Pro MAX is over-all clearer with less conflict between drivers, less cushion fuzz between sonic events, bringing more detail and clarity to the table. No conflict between drivers as the SPA-Pro MAX is utilizing only one 11.4mm full-range driver here, and this is normally surprising as I typically like Hybrids better.
This event may be due to the specific tone that was arrived at with the SPA-Pro MAX.
Meaning TFZ/EarAcoustic Audio really did their homework to add a very evolved DD, a DD that seems to add both treble and bass from a single DD. And while the WM1Z is a standard V shaped affair, the WM1A is more pushed midrange to activate more vocals into hearing the SPA-Pro MAX take added advantage. I mean sure both IEMs go and relate that vocal additive of the Sony WM1A to the mix. And I’m trying not to make this a DAP review, only it can’t be ignored how both IEMs go to tell the tale of vocals better with the WM1A. In-fact……all the extra bass density and treble airiness only goes so far, being overshadowed into entertainment by the Sony WM1A vocal stability here.
Ghost 13 Commandments Call Me Little Sunshine 44.1kHz - 16bit Could the TRI Clarion ear-tips be a big part of this tone? I mean sure this is not an advertisement for the TRI Clarion ear-tips. But maybe in a way it is? Why didn’t I know about these ear-tips before? All I can promise you is the TRI Clarion ear-tips will be creeping their way into a few reviews here from this point on out! I switched the Clarions over to the Penon PAC LS ear-tips on the TRI i3MK3s, and all I can say is, yes they are comparable, only once you hear something………..you can’t unhear it. That yes, the PAC LS ear-tips are also known around these parts of their upper-end intensity and focus. But the Clarions have a wider nozzle circumference going!
Nozzles: Only I’m guessing here, that the slight angle downward from the nozzle opening, actually adds firmness here, needing less material to still get the ear-tip to push back-pressure against the ear-canals physically, and I like that!
Still I would call the two sets of tips equal, only the Clarion does slightly better vocals here. Ear-tips are a big part of the end-result tonal ideas here at Redcarmoose Labs. So much so that it has me questioning my choices to use different ear-tips in my comparisons here.
Really though the two ear-tips are interchangeable. With the PAC LS ear-tips and the Clarion ear-tips each allowing for slightly different ideas of IEM character to shine through. Though not as much of a difference to still hear the character of the drivers to shine through, as each IEM here are really opposites in what they go about doing day-in and day-out.
Call Me Little Sunshine: Going for the midrange blast here with the Clarions with the SPA and the WM1A. Here, yes we have a midrange and treble brightness with the SPA! Yes, bright and forward, almost too much, especially after spending a big part of this reviewing process with the WM1Z. Switching back to the Penon LS ear-tips. Also in the EarAcoustic Audio SPA-Pro MAX…..the PAC LS ear-tips give a slightly better reassuring feel to the IEM fit process, and maybe it is the shape, but the added bass is also an attribute over the Clarions here?
Yes, now I’m sure of it, that the PAC LS ear-tips offer better bass, but the Clarion do better highs. Again I’m focusing on these differences to come to a conclusion that part of the IEM objectivity is influenced by the ear-tips used........of course. Typically I will use the same ear-tips to do these side-by-sides, and here I’m finding myself in a slight conundrum. LOL
Anyways: Back to the basic use of the PAC tips used with the SPA and Clarion tips used with the i3MK3…….I find the WM1Z to be really the slightly more real, and offering a style of playback with the SPA that while slightly less Hybrid separated, coming off more real sounding than the TRI i3MK3 and with that more uniform and filled in, filled in with a natural wholesomeness that just doesn’t stop.
Here is the thing……a super fast change-out of the IEMs with their own cables and ear-tip, onto the WM1Z on its charging base, relays the differences found here.
That the TRI i3MK3 holds a slightly thinness of note weight, only that thinness is not a drawback and I hope it doesn’t come across as such. That emerging from this style of a little less note density comes about a separation and even contrast. A contrast that I didn’t know I would find. This contrast allows extra imaging separation and location into specific parts of the stage. Honestly, during preview listening sessions I thought of the TRI i3MK3 not having as much contrast, and sure maybe it is the WM1Z offering these attributes, only they are unarguably there today.
This wholesome bass (while less than the SPA) is fully fast and allocated to its own zone in the stage. The TRI i3MK3 does hold a slight buzzy air, yet better timbre than you would guess by it being a 10mm Planar driver. I wonder if this use of the Knowles dampeners are working their magic to stifle any Planar timbre, because this sounds almost the farthest from what you would expect from Planer treble use?
The Sonion 2356 BA: The Sonion 2356 BA seems to be held inside a cradle by the bass density and treble density. Meaning other than an all BA set-up KBEAR is exploiting the nearby driver character to kind of smooth out and take away any BA timbre or faster note decay normally found with a BA. Also the use of a namebrand BA goes miles to add to the quality here. Also for the most part both IEMs today are showcasing a balance, that while the TRI i3MK3 is more sub bass oriented and more midrange forward in style, both are heard as very good and complete, even and correct. It is just that the EarAcoustic Audio SPA-Pro MAX held a slower and more filled out low-end, that the sculpturing done by the TRI i3MK3 seemed cleaner and obviously faster.
The EarAcoustic Audio SPA-Pro MAX: The EarAcoustic Audio SPA-Pro MAX is totally different in that there is an ounce midrange and upper midrange clarity, due to none of that frequency buzz of the Planar in use, and while a little less upper midrange exploitation by the BA and Planar of the TRI i3MK3, what we end up with is still a dramatic pushed vocal presentation, yet with a feeling of more naturalness and sculpted poise to the idea of more refinement!
Both IEMs are totally fun in their own correct way. Just that the upper midrange guitar frequencies are more prominent with the TRI i3MK3 creating their own thing into the stage, where the SPA-Pro MAX is still doing those guitars, but they are more natural and integrated into coming off more both together and possibly real sounding, but lacking the contrasts and separation the TRI i3MK3 does without trying.
Side-by-side conclusion: My surprises in this test is that one, I thought the SPA would hold a better perceived note-weight, and it does, only the TRI i3MK3 in the end was way better at note-weight than I could have imagined, until I tried the two back to back. Obviously the volume difference was even more noticeable between the two. In the end the SPA created an extra lower stage added lower midrange girth (and down-low details) as opposed to the upper midrange stage-size created by the tuning focus of the TRI i3MK3. These thinner stage ideas of the TRI i3MK3 are a little faster being introduced and taken away. This TRI i3MK3 personality (while fun) offers a less realistic approach, that while excelling in some technicalities, remains slightly more synthetic in the end. Also just to add, the SPA fits just slightly better (more all encompassing) due to being larger and having a slightly longer nozzle, but again this is nitpicking as the TRI i3MK3 is a little less noticeable and fits fantastic.
Music: The TRI I# MK3 has had 6 days of continuous burn-in. I’m using the included cable and large included ear-tips here. The DAP is the WM1A with no EQ.
Kaveh Cohen, Michael Nielsen Forza Motorsport OST Brotherhood 44.1kHz - 24bit Timestamps only pertain to digital file, not video.
This track I use all the time, hence I know it well. And while only 02:13 long, it serves a purpose both as a game soundtrack and testing tool here at Redcarmoose Labs. The first thing we notice is a smoothness and cohesiveness that is unusual for Hybrid IEMs. What I mean is the Knowles dampers and driver arraignment seem to blend this idea of sound design into an easy to digest affair. So just like the feel-good size and shape the TRI i3MK3 goes about its day being very easy to get along with. Also this is a style of generic theme music that sits in the background adding drama in its own small unassuming way. And the TRI i3MK3 is in a way just like this song. We don’t have total sparkle, or total bass fireworks at hand. So in a way, there are subtleties for the taking, Such cohesiveness and polite drama is found like when we first hear the bass in this song. The extra width of the stage is added to by lower midrange and midbass energies! At 00:43………this kind of watery fluidness that adds to the fluidness already at hand with a song like this. Then there is the drum sound starting at only 00:08, a metronome of sorts. Creating a non-wavering pace that all it seems goes along with. And it turns out I have used this simple sound to judge tone. Where the tone can be played back a multitude of different ways, with the drum sounding thin or like a slap or thick and tonally full. Here actually it sounds relatively natural, which goes against my expectations, but this is maybe the key to the TRI i3MK3 success? That even while this sound doesn’t have a thickness to it, like some IEMs portray, at least we have a tonal correctness here. Also the tone is not abnormally forward in the mix adding to noticeability, but a correct even replay, just keeping its head above water, and I like that.
While sure I have heard this song thicker and even more inviting due to that thickness, the other IEMs at times have done other things which can stand out in replay, to where the best part of this song is how the TRI i3MK3 seems to somehow allow for every aspect to stand-out and shine. Here we have the full idea of replay, and better than full, there is a thickness that I didn’t expect the TRI i3MK3 to do here. A fullness and thickness that seems to add to the note-weight provided and weights even the music down to this very accessible and listenable tone in the end?
E-Mantra Stapanii Timpului Ravenmocker (Original Mix) 44.1kHz - 16bit Probably the main question here is if the TRI i3MK3 can do this bass. And if you are wondering why I included this song, that’s why. Let’s just say when the bass is this reserved, genres like the Trance genre get questioned as to the playability. Does this sound like Trance played out of table-top radio? Hello, that is why if you go and listen to Trance in a live avenue setting the bass is normally the first thing you hear, you hear it when you get out of your car, or you hear it while walking to the place where it is played live outside....maybe? And sure, this is not probably the greatest genre, for the TRI i3MK3, except I like this style of playback. Why? For starters the bass is sub-motivated and with that comes a style of speed and clarity in that the midrange of this music is heard to its fullest potential. To where there is a nice occurrence of this clean bass which still takes authority and size, it is just not all encompassing like some bass heavy styles heard. What this instead showcases is the large synthesizer additives, the smaller tics of slight rhythmic beeps and boops. Only these additives are way more out-front than you would guess. Holding a prominent style of midrange size into the stage, only when the sub kicks there is a speed of clearness obtained, with nothing left in its way! And the Planar driver is fast, showcasing a great tone obtained in the upper realm……….projecting all this speedy imagery that seems way faster than normally heard and taking extra notice! Gone is that thick lower midrange soup that you would normally expect, and instead is replaced by a faster and entertaining mid-range explosion of imaging and quick contrasts way outward to the reaches of the stage. Even the bass has very little decay, and on paper this reads like a no-go, only it is very fun and could even be the desired way to hear this song, though far from the normal way of cooking your music, call it diet or low carb, it is refreshing to hear none-the-less, and I mean that!
Hans Zimmer Inception OST Old Souls 44.1kHz - 16bit Look, in many ways I view this like the last song. Why? Well the bass here is a big part of both hearing this for the first time, and the remembered way to hear it again…………in regular music listening enjoyment. To be sure these are faster bass IEMs, and almost diminished bass IEMs. So what we get would be if you listened to your parents giant furniture console stereo with extra bass your whole life, then went over to your Audiophile Friends house to hear an anemic bass played back. Only the difference is these are really not bass anemic, what we get is fast and detailed bass, though probably a basshead would take issue here. Again here we are in the very center of midrange forward relay. Though what takes the stage is both a very reserved style of playback, holding a tone where nothing is too much or maybe too little? As such we have a decent replay, and really enough for the money asked, yet slightly compromised with this non-vocal style of music. Plus listening to other tracks, the emanate blast of drama is somehow slightly lost with this mid centered affair?
To where switching to a more bass heavy source is a band-aid for this issue, though not the end-all end-all……..as this style of music (for me anyway) needs more lows. Funny too as the previous Trance song actually worked due to there being enough bass, only here we are counting on the lows for more of a song message.
Packaging:
Cable: The 612-core 5N OCC Silver plated affair actually comes off thick yet well behaved. The cable very much reminds me of the SIMGOT AUDIO LC7, though this one is not modular in design. Note the close-ups of the plug in-use………the chin-cinch never slides out of place unless you move it to, and I like that. Coming in with a 4.4mm plug was another gift!
Features:
>3rd Generation Hybrid Flagship IEM.
>3rd Gen Planar+BA+DD Hybrid Configuration.
>10mm Planar Magnetic Driver.
>10mm Beryllium Diaphragm DD Unit.
>Sonion 2356 Mid-Range BA Driver.
>CNC Machined Metallic Housing.
>Premium Finish With Anodized Oxidation Process.
>Three Pairs of Knowles Acoustic Dampers.
>2-Pin 0.78mm Connectors.
>612-Core 5N OCC Silver-Plated Coaxial Cable.
>4.4mm Balanced Termination Plug.
>11 Pairs of Ear Tips.
Conclusion: Wow, really this is something which simply shows the IEM climate now in 2025. With a fast and still fairly reserved bass we are once again more focused on the mids. The treble does the same being a single 10mm Planar offers both a smooth treble, yet not overly bright or even totally Planar sounding, except for a few moments here and there. Really to me the Sonion 2356 BA is the star of the show here.
What I mean is typically in place Planar Drivers can have a definite sound character, and while this is slightly true to the overall sound of the i3MK3, the Planar drivers is very much set back along with the 10mm bass driver, to push a kind of midrange balance. When you add-in the fitment and feel, the weight of only 6 grams, and the form factor here, there is a lot to appreciate. Again it is obvious the TRI did their homework and spent a fair amount of effort to design a well rounded and well liked IEM introduction. Sure bassheads will not maybe be satisfied, nor the treble heads looking for brilliance up there, yet the mids where 85% of the musical information sits, are well done and emotionally involved. As far as technicalities go the i3MK3 is not the quickest set on the block, nor does it have the biggest stage, still relative to its price-point it is fine. A sub bass emphasis yet overall neutrality in tune. This overall softness is actually my favorite part, in that there is a slight wash to everything which in truth works to add listenability and musicality. That underneath it all this DD bass comes through to hold its own area inside the stage. I will use the very first adjective that came to mind while listening to the i3MK3, and that is romantic, there is a softer and ever so slight slowness that makes the actual tone very digestible, with no rough edges or too much bass or sparkle. This idea is all the more promoted by the Sonion vented BA driver, a unit that gives wonderful realistic midrange and prominent vocal replay.
Vocal IEMs: Remember I said I thought the sound design was focused on the mids? What surfaces is an IEM that does female vocals slightly better than male vocals, yet does general vocals with a pizzaz. Here the Sonion BA pushes vocal frequencies and leaves the artifacts of any slowness left out. To where the vocals emerge clean and correctly positioned in your favorite song, only surrounded by the upper Planar slight fuzz, and lower sub-bass energies which are careful. It was this 3D vocal push that was first noted upon first impressions, which still holds true due to performance quality.
If anything burn-in added a cohesive quality, smoothed-out the Planar treble a little, and tightened the bass action. Of course much of this could be brain-burn-in, yet this overall tonal placement I regularly like. This mid-centric playfulness in both familiar and also the Planar tone adds a bit of slight color in the form of artifacts, which may end-up fun or at least different for your average listener. That this fast bass and slower attack of everything else creates a distinct personality apart from your everyday IEM.
At a price of $219.00, in one color.......I hope you like it!
Disclaimer: Thank-you to Evelyn@keephifi.com for the i3MK3 IEM review sample.
Disclaimer: The TRI i3MK3 Universal IEM has had a total 6 days of burn-in.
Disclaimer: These are one person's ideas and concepts, your results may vary.
Equipment Used: Sony WM1A Walkman DAP MrWalkman’s Firmware 4.4mm balanced Sony WM1Z Walkman DAP MrWalkman’s Firmware 4.4mm balanced Sony TA-ZH1ES DAC/AMP Firmware 1.03 in 4.4mm balanced Electra Glide Audio Reference Glide-Reference Standard "Fatboy" Power Cord Sony Walkman Cradle BCR-NWH10 AudioQuest Carbon USB HiBy R3 II DAP in 4.4mm balanced ifi Go blu Bluetooth Amplifier and DAC 4.4mm balanced ifi hip dac 3 Amplifier DAC 4.4mm balanced
