TRI KAI x HBB English Review


The Sand and Sea Of Hawaii




Construction and Design




  • Slightly warm and safe tuning, fun and pleasant.
  • Musicality suitable for hours of enjoyment.
  • Remarkable low end.
  • Harmonious mids, of medium and smooth presence, free of sibilance.
  • Level of construction, materials used, precious finish.
  • Great packaging, very good level of accessories, with a stellar case.
  • Good cable/sound profile association.
  • Conceptual design.




  • Slightly large and subtly heavy.
  • The cable has no adjustment pin and there is no choice of balanced plug.
  • Controlled treble presentation, secure, but not very extended.
  • The mid-range is felt in the middle distance, which limits the exposure of details and their level of resolution.
  • Eminently frontal scene.
  • No analytical technical ability.
  • This is a very personal opinion, but I would have preferred a colour other than gold. Even so, the contrast with the blue enhances the whole.


Purchase Link


Link to the Store


From 1 to 12 November, there will be up to 50% off in the AliExpress shop.




You could say that TRI is KBEAR’s premium brand. It is true that the parent company has relatively high-priced models, such as the Aurora or the Ormosia. But it is TRI that puts the high-end designs on the market. These include the Starlight, Starshine, Starsea, I3 Pro, Meteor and TK2. Their latest release is the TRI i ONE. In between, there is this collaboration between TRI and HBB (HawaiiBadBoy), called KAI x HBB. It’s an IEMS with a 9.8mm dynamic driver and DLC diaphragm, all inside a golden capsule, almost completely, except for a part of its outer face, which is a medium-bright blue, reminiscent of the sea, in honour of their collaborator from Hawaii. The gold is meant to be reminiscent of the sand on the beach…
Constructed from aviation grade 7 aluminium alloy, the capsules have been manufactured on a 5-axis CNC machine to provide a highly polished and delicate surface.
In Hawaiian, «KAI» means water. And the tuning has been consistent with the name, with powerful bass and a mid-range suited to naturally reproduce the sound of vocals and instruments. The treble has been adjusted so that it is balanced, without being too harsh, and does not disappear too quickly.
Leaving aside the considerations that come from the brand itself, there are always three things that can happen when I have to review a product: I like it, I don’t like it or I am relatively indifferent to it. It is also true that these three options are not always absolute and there is a big gap between them all. On this occasion, KAI are on the fun side of IEMS and are the kind of models I like to have around to enjoy the music. Now we will see why this is so.





  • Driver Type: Dynamic with third generation 9.8mm DLC diaphragm.
  • Frequency Response: 20Hz-40kHz.
  • Sensitivity: 114dB @ 1kHz.
  • Impedance: 36Ω.
  • Jack Connector: 3.5mm gold plated.
  • Cartridge Connection Type: 2Pin 0.78mm.
  • Cartridge Material: Aluminium alloy.
  • Cable Material: 4 cores of high quality OFC cable, silver plated. Each core has 24 strands of 0.05mm diameter, 96 strands in total.





The TRI KAI x HBB come in a small rectangular box, dimensions 95x80x44mm. It is painted with a blue flowing motif, with yellow, even greenish strokes. On the main side, in the centre is the model name, simulating handwriting, in white. Underneath is a stripe, then the model logo, the model name, the HBB logo and these initials. Behind it are the specifications, in Chinese and English, as well as the brand name. After removing the cardboard, a white box can be seen. On its upper side is a lid with the same symbol as the model name, this time in gold. Removed from the lid is a soft brown leather case with the TRI logo. Underneath is a manual. Inside the case are all the accessories, cable and capsules. In a nutshell:


  • The 2 TRI KAI x HBB capsules.
  • 1 silver plated OFC 4-core cable.
  • 1 cleaning cloth.
  • 1 cleaning brush.
  • 3 pairs of translucent white narrow core silicone tips, sizes SxMxL.
  • 3 pairs of wide-core translucent white silicone tips, sizes SxMxL.


The capsules come in a zip pouch. In addition, they have a plastic protector on the outside. The gold-plated 3.5mm SE connector is protected by a plastic sleeve. The cable has a white velcro strip for safe storage.
The contents of the box are sparse in terms of tips, there are no foam tips. But it comes with a cleaning cloth, which is of a very acceptable quality, and a small brush. These are accessories that are not very common. On the other hand, I would like to point out the tight packaging size, the leather case with magnetic closure and the double protection of the capsules. Sometimes you don’t need a very large size to have a high level of packaging. Very good.



Construction and Design


The capsules are made of aviation grade 7 aluminium alloy and manufactured on a 5-axis CNC machine. Their surface is highly polished and delicate, a real magnet for fingerprints, which is why they come with a chamois cloth as an accessory. That’s a nice touch. They have a semi-custom shape, resembling a triangle-rectangle with fully rounded corners. At the upper vertex of the supposed hypotenuse, there is the 2PIN 0.78mm connector. At the bottom, there is the TRI logo. The outer face has two parts, let’s say that 70% is occupied by a dark turquoise blue L and the remaining part is gold. On it is the HBB logo and the full name of the model, in the same blue colour. The inner side is completely gold-plated. Near the 2Pin surface connection there is a hole. There is another one near the base of the nozzles. The inner face stretches towards the nozzles and the nozzles start from a step to its edge, measuring only 4mm. The outer crown measures 6mm, while the neck measures 5.3mm. There is a perforated opaque metal grille. The inner face has a small bulge on the side opposite the mouthpieces, but the whole is very rounded. The capsules are medium sized, but it has a good thickness and the mouthpieces are not very long. You could say that the weight is noticeable, but not annoying.
The cable consists of 4 high quality silver plated OFC cores. Each core has 24 strands of 0.05mm diameter, 96 strands in total. The cores are wound together. All parts are cylindrical and gold-plated, there is no adjustment pin. The cable has over-ear guides. The 2Pin 0.78mm are mounted on a plastic base which integrates very well over the capsules. There is a coloured dot, red or blue, on the short side of the plastic base containing the 2Pin, to indicate the channel. The design, the shape, is not bad at all. But I don’t like the gold colour, so that aspect is a minus point. On the other hand, the blue is nice and the design of the outer side has its point, with that mix of two parts and their open L-shaped separation. The logos drawn on these sides accentuate the quality of the finish, which is extremely smooth and soft, but still susceptible to fingerprints. The weight, due to the metal construction, is noticeable, but not excessive. I do miss an adjustment pin on the cable.
The case is made of leather, it looks real, it even smells. It has an oval edge and the logo is marked on the flap. It has visible stitching, a closure with two small magnets on the flap and a black velvet lined interior. Very nice case.



Adjustment and Ergonomics


Due to the size of the nozzles, the insertion is shallow. The adjustment is simple and free, it allows a slight movement, because the lateral protuberance is light and does not touch the ear, at least in my case. This effect has a double consequence, it doesn’t bother but it doesn’t anchor either, hence the possibility of a slight twist inside the ear. The over-ear cable is perhaps a little more twisted than it should be and when I have been wearing them for more than an hour, they don’t make contact behind the ear, which is slightly annoying.
Although I mentioned that the weight is noticeable in the hand, it is not very noticeable in the ears, thanks to the firm and durable fit. It is suitable for everyday use, for walking and strolling at a good pace, it doesn’t fall off or move around.
The insulation, with my foam-filled silicone tips, is quite good. The thickness of the tips makes the pressure against the ear canals a bit higher and the occlusion level is higher.







I don’t always enjoy the IEMS I review. There are times when I have to be strict with myself and review the product from a more neutral and aseptic point of view. Clearly, this can influence the final assessment, but I think readers will forgive the bias of each reviewer. But, in this case, it’s the other way around, because I liked these IEMS from the first listen. It is true that I would prefer a little more extension in the treble, as the TRI Meteor or the Letshuoer S12 do have. But it is also true that both are more expensive.
The TRI KAI x HBB are IEMS with a light, tiny U-profile, as I like to say. They have focused low end bass and subtly emphasised mid-highs. The treble control roll-off is subtle, but the overall package is neutral and smooth, pleasant and well presented. This is a model that has a tuning I like, whose low-mids are not too deep and can be enjoyed from 1kHz upwards with confidence and for hours on end. The emphasis on sub-bass makes them a lot of fun to use with electronic music, but I wouldn’t call this a bass-head set, it’s more ambitious in this respect, but without the extension or greater balance of the Meteors.





Of course, the bass comes from a large dynamic driver, with all that that entails. The DLC diaphragm has some great virtues and the rest is the work of accurate, focused tuning in the lower range. It’s not the most compact or precise bass there is, nor is it the fastest, but it is truly deep, dark and expansive. Despite its predominance and extension, it is relatively clean in the midrange, thanks to its emphasis on the extreme sub-bass and descending towards the centre, without stopping in the mid-bass. I notice a slight rubberiness in its execution, but it’s nothing alarming, it just adds a little more body, a not so fleeting decay and a little more punch, an enjoyable aftertaste, by the way. You can tell that the driver has been tuned more for fun than to be technical. In this way, the hit is powerful, but not completely tight or dry, but there is a point of excitement and juice. Most of the time one prefers to have fun, enjoy and forget about it. And the KAI is the perfect ally for this, but without losing sight of the other frequencies, not just a good quality level.
Texturally they have a good middle ground, not the roughest bass I’ve seen. But it does have a mixture of descriptive darkness, mixed with a certain thickness, which gives that physical, corporeal touch to the surface of the bass. In this way, the lines are easy to follow, thanks to the physicality of which I speak. But they also have the ability not to blend together and to stay in place. All this contributes to create distinguishable layers. They also have the ability to handle complicated, complex, swollen and muddy bass passages with skill. The only thing I would argue is that their presence in time and space may be limiting for fans who don’t like that amount of bass. But, for me, they are just fine.





Despite the emphasis on the sub-bass, I notice a point of warmth in the first half of the mids. The bass is bigger and more present than the mids, that should be clear. But it is not a recessed or distant midrange. There is a good presence on its own, much more than a more pronounced tuning could give. So, that’s why I like to call it a lower case U-profile. And that initial warmth benefits male voices more than female voices. Both are full-bodied, but the female voices are drier, have less sparkle and shine. It is noticeable that there is not so much humidity here, nor is the presence of the female voices very prominent, remaining at a middle distance, which does not possess such descriptive capacity, nor such complex, rich or nuanced behaviour, as the male voices or the instrumentation of the first half. Not that this first part is far superior, but I notice that qualitative distinction. Something similar happens with the timbre of the instruments that require more harmonics, they lack that point of vivacity to sound more complete. It seems that this more secure tuning has also influenced the second half of the mids. In this way, the central range has a more accentuated neutrality, which is adequate if not too much is demanded of it. And I speak of neutrality in terms of restraint, rather than homogeneity, balance or naturalness. In that respect, the timbre is more sparse, less complex or complete. On the other hand, that doesn’t detract from its enjoyability either, most of the time. With neutral or analytical sources, the ensemble is very pleasant, harmonious and attractive, even with a point of organic euphony. As long as I have been enjoying the KAI I have had no problems with the mids in any case. But the moment I have moved on to analysing them and being stricter, I have discovered that this tuning benefits the bass more than the mids and forgets, a little, certain abilities that would have favoured the central range to a greater extent, to make it more exciting, luminous and skilful.





The trebles are presented in a way that may seem simplistic. They do their job well, but without being overly lavish. They seem to be infected by the complacent air that the midrange possesses. There is initial sparkle, the control decay is adequate, enough so that the treble does not seem sloppy, but, rather, smooth and pleasing. The emphasis is just right, on the gentle side of things, but without taking risks. While safety and smoothness is its plus point, that unwillingness to take risks and be more ambitious limits the potential of these IEMS. It is a permissive and sufficient tuning, which does not want to go further in its boldness. Thus, the treble is drawn with a thickness that is also average, not too sharp, its emphasis is limited and its brightness restrained. This is how the area is covered with a good initial attractiveness, which allows the notes to be executed with a good sufficiency, but without a rich or more necessary extension, appreciating, also, a lack of air in the upper end. In the same way, I am again strict with some IEMS that I like. But it happens that sometimes you get more out of the things you like the most than the things that matter the least.



Soundstage, Separation


The scene is characterised by a good level of depth, laterality and average height. It is not a very gaseous environment, nor is it a diffuse scene. The level of expansion is not very high. Thus, the presentation is relatively natural, without forcing. Frontal perception predominates, because the sound is not very surrounding. The positioning of the elements is adequate, not too specific, but it has an acceptable location, even if it is frontal.
The level of resolution is quite decent, although they are not the most detailed IEMS in this price range. I perceive that there are hidden nuances that I know in key songs, which try to resurface, which is quite positive. There are similar alternatives that don’t even get to that point. But I have to conclude that it is not a matter of enviable technique or very high exposure.
The level of separation is good, the sound is clean, but not crystal clear. Being a bit dry and warm, with a thickness of notes tending to medium, the cohesion of the elements is higher. Nor is the sound analytical or too neat. There is transparency, but neither the background nor the separation is stellar. Everything is in keeping with the price and the tuning, as well as the level of air it possesses. I should make it clear that these are not muddy IEMS, far from it. But the set of technical skills and sound signature contribute to a more harmonious, musical, cohesive and smooth sound, more suitable for the enjoyment of music than for monitoring.





Letshuoer D13 Silver Filter


Priced, as of the writing of this review, at 118€, compared to 87€ for the TRI KAI (you can tell that 11.11 is coming), the D13s have a tuning with the silver filter, which is very close to the KAI. At first glance, the D13s have a bit more mid-high end and the treble is not as restrained. Although the amount of air is similar. It is clear that a very favourable point of the D13s is that they can change their profile, especially in the second half of the frequency range, thanks to their screw-in filters. With the gold filter you get more sparkle, light and joy. While with the silver filter it is closer to the KAI tuning, although they are not the same. For this test I have used the Silver filters, so that everything is as close as possible.
Going back to the beginning and comparing the shape of each, the KAI’s use a larger and slightly heavier capsule. The ergonomics of the D13s are very good and the comparison is immediate in this respect. The Letshuoers adapt like a glove, they are smaller and the fit is immediate.
Speaking of sound, testing with my bass-rated tracks, the first thing I feel is that the D13s are lighter and have a more concise punch. The KAI’s are darker, harder to move and a bit more opaque. The sub bass of the TRIs seems more rubbery, but also a point deeper. You get the feeling that the amount of air moved by the D13s is superior. But even with that, the punch is faster, drier and more restrained. There is a clear difference in the bass colour of each model. The D13s seem slightly more coloured, with a more noticeable kick drum punch. The darkness I’m talking about in the KAI offers a more sensory bass, with a timbre more shifted to the sub-bass. There seems to be a bit of a mid-bass shift in the D13s, which makes them rounder, but also more decongested and cleaner. The bass lines are different in both. I think I see a little better technical quality in the D13s, being easier to follow and execute more complex and bass-heavy passages.
In the middle zone, the first half of the KAI is more physical and corporeal, carrying warmth, density and a hint of darkness from the lower zone. The D13s are cleaner and lighter, possessing a lower physicality, which makes them clearer and more transparent, but also thinner. This is noticeable in passages with strings and male voices. There is a higher presence in this first half in those of D13. In this way, the mids are more perceptible, clearer and more pleasing, becoming more exciting, detailed, richer, even more exciting. What is achieved with the D13s is attempted with the KAIs by turning up the volume, but this part is not as evocative as in the D13s. This is how, despite being thinner, the tone is more complex and the timbre more realistic. The level of detail and clarity of the D13s also plays a role. That point of elevation in the high-mids provides more than just light, because the driver feels more technical, precise and resolute. In the KAI’s it feels like something is lost due to its mid-light, mid-distance and greater opacity/warmth. I don’t find either to be the IEMS for female voices. But, instead, the KAI’s present those voices in a thinner form, as a counterpoint to the male voices. In D13, they are closer and that richness of nuance is felt more blatantly. The same is true of the instrumentation. The KAI, with that middle distance, offer an exposition in the same way. Hence the enjoyment feels curtailed, in pursuit of a more sparse, less descriptive and slightly more distant presentation.
Even with the Silver filters, the initial punch and treble extension of the D13s is superior. On a prolonged and extended treble hit, you feel the comparative limitation of the KAIs, which offer a simpler, less extended and smoother treble exposure. The high notes climb higher, are thinner, but also more prolonged. There is more sparkle, brilliance, sharpness and finesse in these Letshuoer treble notes, gaining in resolution, detail, nuance and transparency. In air quantity things are equal, but the better inertia of the D13s helps them.
The warmth, the dark point, the depth, the lower rate of transparency and separation, offer a more frontal and intimate scene in the KAI. The greater amount of air and luminosity of the D13s gives you a more visible separation, a better laterality and stereo effect, a more open and expansive sound. While also no prodigy of detail, openness and stage size, the D13s offer a larger, more expansive soundstage.
In the end, the €30 extra for the D13s is noticeable, but also the similar tuning, but brighter at key points, helps the Letshuoer cost the difference. Meanwhile, the KAI performs very well in its range offering many virtues, great packaging, construction and fittings, with a warmer and smoother tuning. And this has to be taken into account.





The TRI KAI x HBB are very well built IEMS, with a gold and blue (thankfully) design that has its own symbology (sand and sea), in homage to its tuner (Hawaii Bad Boy). They have a tiny U-signature, with emphasised bass at the lower end (sub-bass), it is powerful in this range, slightly thick, yet dark. The midrange is slightly warm, harmonious and musical. It is restrained in its upper part and lacks sibilance. But it has a quite enjoyable presence. The representation of the treble persists in that idea, maintaining the coherence of the smoothness of the central range and a more simplistic expressiveness, in a way that allows the sound to be approached from a point of view more appropriate for enjoyment, rather than for more critical or analytical listening. In this way, I think that the KAIs have been conceived for fun, but without renouncing to a qualitative level that reaches the remarkable. Something that makes them loyal friends, because they provide me with the bass power I usually look for, a midrange that has a good presence and a treble with just the right spark for an enjoyment without too many pretensions, beyond spending many hours together. To all this is added a setting that allows long listening, a concise and contained packaging, with a great leather case. In the end, that’s what it’s all about, isn’t it?



Sources Used During the Analysis


  • Hidizs XO.
  • Earmen Angel.
  • TempoTec Variations V6.
  • Hidizs AP80 PRO-X Red Copper Limited Edition.
  • ACMEE MF02s.
  • xDuoo XD05 BAL.
  • S.M.S.L Sanskrit 10th MKII + iFi ZEN CAN.
  • Burson Audio Playmate.