YinYoo Topaz Review

Price: 100€

Where to buy them: [link]


  • Frequency response: 20-40k Hz

  • Impedance: 12 Ohm

  • Sensitivity: 106±3dB

  • Connectors: 2pin 0.78mm

  • Driver configuration: 1DD+4BA


Many thanks to AK Audio for providing this review sample and an upgrade cable. You can always get a little discount by buying earphones by them, if you write “techinblack” as a message for the seller before paying anything. This is not an affiliation: techinblack doesn’t get anything if you do like that, but you can pay a little less. It’s all for the music. Peace.


Unboxing and first impressions

Similarly to other YinYoo earphones, the Topaz come in a shiny blue cardboard box, which contains a classic hard case, which in turn contains the buds, the cable, a clip and the eartips (S-M-L wide bore and S-M-L small bore: 6 pairs in total). AK Audio sent me an upgrade cable, which you can buy together with the Topaz. As always, there’s a complete set of accessories; the only thing I would have added is – at least – a pair of foam ear tips: this is a 100$+ contender and the others usually have a pair of them (BGVP/NiceHCK/BRAINWAVZ…). The stock cable is the same cable as the YinYoo D2B4 (here is not MMCX but 2pin), surely a tool but honestly bad looking and too rubberish. The upgrade cable you can choose is very similar to the BGVP DMG silver cable, a very good one overall, especially for the price. The buds themselves are amazing: great looking, with a nice choice of materials. They are made of metal and they may be an answer to IKKO’s OH1/OH10 in terms of design, even though the Topaz are more regular in their shape. You can see the vents for the dynamic driver precisely cut on the shell. I don’t know why YinYoo tends to produce different models with different connectors, but as long as there are compatible upgrade cables, it doesn’t bother me at all. In the end, I’ve paired them with a TRIPOWIN C8 cable, which is fantastic. For the eartips, I enjoy the foams which come with the AudioSense T800, they improve the fit and the isolation, which are not the stronger points of the Topaz.



My sources: FiiO M7, Mi MIX 2 with DAC Zorloo ZuperDAC-S and MacBook Pro 2012 with USB audio interface Focusrite 2i2 first gen, iFi xDSD and XDUOO XP-2

My files: DSD, FLAC, ALAC, MP3, M4A

My music: “Colour the Small One” by Sia, “Djesse Vol.1” by Jacob Collier, “Where are You?” by Frank Sinatra, “Ghost Stories” by Coldplay, “O” by Damien Rice, and many other tracks by Queen, Pink Floyd, Genesis, Radiohead, Billie Eilish, The Bloody Beetroots, …

I didn’t have the highest expectations for these Topaz, because the last YinYoo I’ve tried (D2B4) really left me a sour taste. Instead, I actually found one of the better sounding earphones of my entire collection. I didn’t expect a sound that balanced and close to neutral for an earphone that’s still mass-oriented. If you’re familiar with the Tin HiFi T2, you’ll understand this sound. It’s extremely clear and transparent, airy and spacious. The Topaz are a little more bassy than the T2, and they are superior detail-wise. That being said, the bass is extremely controlled, the mid-bass is not emphasized at all, and you can hear a good sub-bass rumble. The speed of it is pretty standard, for a dynamic driver you may expect a little more body, but again: this is a close-to-neutral IEM, and it can be recommended for music production thanks to its flatness. Mids are great: comfortable, a little notched, but pleasantly airy for vocals, and well layered for instruments. I like how everything sounds very balanced, without any emphasis on certain frequencies or instruments. Earphones like the AudioSense T800 – which I borrowed the foam tips to – are much more vocal-oriented, even though the instruments don’t feel undertone. This is a really different tuning, and in my opinion for a hybrid it’s a very well-done one. Treble is clear and airy. No noticeable sibilance there, no harshness, but a touch of brightness which is good as long as you need to hear the details and perceive the stage. Vocals are pleasant and feel natural even on the high range. The soundstage is wider than average, while just average in its depth. Imaging is very good: even though there’s not a crazy wideness, the precision of the position of the parts is impressive. Speaking of isolation, the shape is not particularly ergonomic like it may seem, so it’s not that easy to get a good seal with the stock tips. Yet, if you use a good pair of foams, that helps a lot on improving the fit and the seal and you get less leak on the bass side.



YinYoo D2B4: they are much more bassy and V-shaped. The sound of D2B4 is congested, too much for my taste, it resembles a bad version of the BGVP DM6 tuning. Luckily, the Topaz are a giant step up from the D2B4 in terms of tuning, clarity, stage perception. These two share the same difficulties in ergonomics, for my particular ears, but it’s a side issue because you can improve that with some foams. I wouldn’t recommend the D2B4 to many, because I feel like there are better choices on the same price range, with the same (good) build quality, like the NiceHCK M6 or TinAudio T3. Instead, I would recommend the Topaz to the ones who need a good tool for production or need to listen to music with a high fidelity. Absolutely not for bassheads.

Tin HiFi T3: their tuning is different from the T2’s one, which is closer to the Topaz’s one. But the T3 are more comparable due to their improved detail and bass. I personally don’t think there’s one absolutely better than the other, but they are different products. T3 are more sibilant, or let’s say less gentle in the high range. And they are more bassy. If you like a balanced, yet fun listening, they would be a better choice over the Topaz, which are much more on a neutral side. My personal choice, because of my needs, would be the Topaz (but make sure you get a nicer cable; the stock one does these IEMs no credit).

BGVP DMG/NiceHCK M6: these two siblings are just fun. Very bassy, heavily U-shaped, I love them but they are not meant to be used as tools for production. They are good live stage monitors, though. But if you need something for mixing, the Topaz are more useful. The fit is worse on the Yinyoo, but this could be a personal factor. Build-wise, we are at the same level. I also think the upgrade cable which you can order with the Topaz is the same as the other two, just with different colors and details. Still, if I had to recommend something, if you need a flat sound, go for the Topaz; if you want a versatile IEM for various genres and situations, and especially a fun one, go for the M6: they are very cheap for their offering.

BGVP DM6: strange comparison? 200$ is twice the price of the Topaz. But I’m here to say I’d get two Topaz instead of a single DM6. Or even a single Topaz because their value for money is way higher than the DM6’s one. DM6 are too congested and their stage is too close. Clarity and tuning of the Topaz win over the superb detail of the DM6’s Balanced Armatures. And this is a personal opinion, obviously. I wouldn’t choose the D2B4 over the DM6 as other reviewers said, but I’d go for the Topaz because of their balance. Build quality, tuning, accessories, design: the Topaz are phenomenal monitors for their price.

Simgot EM1: maybe my favourite earphones. Single dynamic driver, an incredibly versatile IEM with a fun yet balanced tuning. They are much more musical than the Topaz, but less precise. And they are a little bit sibilant. Don’t ask me to choose between the two, please. They are so different, but I love them both. No, I choose the EM1.



I don’t have much to say: these are convincing In Ear Monitors. Actually one of my favourite ever. They look amazing, they are crazy well built, their sound is the one I usually search for, and if you find the right eartips, you’ll also find them comfortable and sealed. The price tag of 100$, considered the actual market, is pretty fair. With a better stock cable and some foam tips in the box, I would have paid much more, considering how solid the Topaz are. With the Simgot EM1, they actually are the overall most convincing earphones I’ve tried on a budget. If I had to pick a fun one and a flat one under 100$, these two would be my choices.



  • Accessories

  • Tuning

  • Clarity

  • Natural timbre

  • Flat sound signature 


  • Stock cable

  • No foam tips

  • Bass may be lacking for some


Price: 70$

Where to buy them: https://www.brainwavzaudio.com/products/koel-balanced-armature-earphones

Specifications (from the website):

  • Drivers: Single Balanced Armature

  • Rated Impedance: 30Ω

  • Frequency Range: 16 Hz ~ 22 kHz

  • Sensitivity: 105 dB at 1 mW

  • Cable: Detachable

  • Cable Connector: MMCX

  • Plug: 3.5 mm, Gold plated


This is the first BRAINWAVZ earphone that I try. This is also the first single balanced armature earphone that I try. This is an interesting coincidence, because I’ve tried a lot of earphones. To be fair, this is also my first 3D-printed IEM! As you can understand, there are a lot of curious things about these monitors, and we’re just at the intro.


Unboxing and first impressions

This box has been a struggle to open. That being said, this is a modern yet classy unboxing experience. The internal box has a book-like shape and contains a hard case (which is a serious hard case, one of the best I’ve held), which in turn contains the IEMs and the accessories. There are a lot of tips (6 pairs, 3 measures doubled, and a pair of T100 red Comply foam tips). There’s a clip, a manual, and the cable already attached to the buds. The cable is good and it feels like a tool – much better than the ADVANCED Model 3 (wired) cable, which I find to be a similar pair of monitors in their will. If you look at some KOEL pictures, you don’t have the same good impression as seeing them in person. They are “lucid” to the touch, and I thought they were “matte” by looking at the photos. The shape is very interesting because it’s a bit unusual, with a grip on your lower ear. I have to admit that – even though the fit is really stable – I find the buds to be a little bit too big for my ears, so I can use them for half an hour but after that time I feel fatigued. With the Comply tips on, the comfort is surely improved, because you can leave the IEMs less deep, but still having a fair grip. If you have bigger ears, these will be not just stable but also very comfortable to wear in my opinion. Anyway, the cable has very low microphonics and its 45° plug is perfect for strain relief. I like everything about the design, the look and the build quality of the KOEL. And I appreciate the attention they put on the presentation.



My sources: FiiO M7, Mi MIX 2 with DAC Zorloo ZuperDAC-S and MacBook Pro 2012 with USB audio interface Focusrite 2i2 first gen.

My files: DSD, FLAC, ALAC, MP3, M4A

My music: “Colour the Small One” by Sia, “Djesse Vol.1” by Jacob Collier, “Where are You?” by Frank Sinatra, “Ghost Stories” by Coldplay, “O” by Damien Rice, and many other tracks by Queen, Pink Floyd, Genesis, Radiohead, …

First thing first: I noticed that these earphones generally require more power than average to be driven. Just a few steps more on my FiiO M7, which I primarily use.

It’s important to understand the will behind these earphones. As you can imagine reading the driver configuration, this single balanced armature IEM is not for casual users. As casual users, I mean the average consumers who want a “fun” sound, colored; a sound which makes you wince, an emotional kind of sound. You won’t have that with the KOEL. They are meant to be analytical and detailed. That means their use would be not just music listening, but music production too. As a music lover and as a musician, I liked these earphones. A lot. And my love for them is very different from my love for my Sennheiser Momentum, for example. Because their signatures are very different. The KOEL signature is very balanced and flat, it reminds me the one of the ADVANCED M4. It may sound less “natural” than other earphones, because I feel they are meant to precisely monitor your recordings or live stages. When you listen to music, you may like a touch of color, a slight “V”, and there are a lot of choices for that kind of use. However, I feel the KOEL are really different in their purpose. Even though I still enjoyed them with my music, I didn’t feel the emotion of other sets – like the Simgot EM1. Why? Because balanced armatures are not meant to “move” you, they are supposed to be precise, quick, analytical. This is exactly what the KOEL sound like. There is more. At first, listening to “Magic” by Coldplay, I heard some bad noises on the right earphone. Like there was sort of a driver movement when the kicks were punchy. I’ve never heard anything like that on any of my earphones. Then I’ve searched for the same song – mine is a CD rip-off – on YouTube and Spotify and those versions didn’t have those noises! I guess these earphones are so analytical and “raw” that a bad master (or rip, or something) immediately comes to light. This is crazy, in my opinion. Neither my ADVANCED M4, which I find very similar to the KOEL, have this level of detail and precision. It’s important mentioning that “Magic” was the only song which had this problem. I still don’t understand why I’ve heard that just on that particular song, when I can’t hear any strange things by using other earphones or – using the KOEL themselves – with the same track from another source. I don’t think the problem is on the earphones, because no other track has any issues. But I will deepen that aspect in the future, by trying other Brainwavz models and hearing if that aspect still remains.

So, in a general way, the sound signature of the KOEL is similar to the M4 one, but with a more refined treble. The bass remains that neutral, uncolored bass that I found there, yet being well extended. Some may find it lacking: I think you have to think of the KOEL in another way. They make you hear exactly what the artist recorded. Every mainstream earphone has enhanced bass, and even treble sometimes; the KOEL are absolutely not meant to entertain: they are meant to monitor. The mids are phenomenal – I would say this is a “mid-centric” earphone, but it’s just an impression based on a comparison to more fun earphones. Even though the mids are very well-layered and vocals and instrument parts are perfectly reproduced, that doesn’t mean that bass is lacking quality or treble is rolled off. It’s just a signature that puts balance over fun. So, your treble detail is still there, with nearly no sibilance, but it doesn’t make the overall sound bright. Neither that good bass make the signature warm, because it’s very controlled. And the soundstage feels very wide comparing to my other sets. Only the M4 – I continue talking about them because they are similar – feel that wide and have the same precision in imaging. Overall, you won’t get these earphones for the craziest sub-bass extension, nor for the punchiest mid-bass. You will get them for the balance, the airy vocals, the precision in treble. And I believe that spending 20/30$ more than the ADVANCED M4 could be reasonable for the better treble and the interchangeable cable.




ADVANCED M4 (to summarize): they are very different in every way but the sound. M4 are made of metal, they have a non-detachable cable with a microphone, an L shaped jack and they have a single dynamic driver; KOEL are made of 3D-printed resin, they have a removable MMCX cable with no microphone, a 45° jack and they have got a single balanced armature. Totally different specs, totally similar sounds. It’s pretty strange, considering the different drivers. I’d say, there’s some dynamic spirit on that balanced armatures inside the KOEL. The only real difference I can hear between the twos is the better treble on the KOEL, which is clearer and more detailed. The bass may be a little more present too. I really can’t choose between these two earphones.


ADVANCED Model 3: they are very similar in every way but the sound. I’m not joking, and I usually don’t use earphones of the same brands to do comparisons, but here I have to. Model 3 and KOEL have a similar shape, the same connectors, a similar fit (personally Model 3 are a bit more comfortable), similar build quality but very different sound signatures. So, I’m not saying that M4+Model3=KOEL, but the equation is not so different. Model 3 are made for a fun listening. Mid bass is very enhanced and mids are recessed, treble is fair. The soundstage is way more intimate. So, the Model 3 could be an option for those who don’t appreciate the flatness of the KOEL. I would choose the KOEL, though.


Simgot EM1: I compare them and not the MT3 (which have a closer price to the KOEL) because I fairly appreciated the EM1 and the KOEL, while I’m not totally convinced about the MT3. That said, even though the EM1 are among my favorite earphones, they are pretty different in sound compared to the KOEL. I don’t feel the EM1 as heavy colored or too bassy. They are pretty balanced and neutral, but more comfortable and more fun to listen to, rather than the KOEL. Between the two, because of the better fit, I would choose the EM1. They are different, I like them all, but if I had just a choice, that would be my personal one.




So, it’s important to understand this kind of sound signature: I have a lot of earphones, but the ones with that flatness and balance are just these two that I’ve mentioned (KOEL and M4). While I love many sets for different reasons, I can’t deny that while I need to record and mix my songs my choice couldn’t fall upon a fun sounding earphone: here I choose something like the KOEL. Not for chilling, not even for comfort. When I need balance, clarity, sense of space, I rely on them. That’s good in a way, not-so-good in another. Because if I try to recommend them to you, it can be difficult. I may have your same taste, but not your same needs. If you record or monitor music, these are perfect for the money. And even if you are crazy about high fidelity. If you want something more relaxed, more bassy, there are plenty of options. But I think you must give a try to the KOEL, or another flat earphone, to really enjoy the details usually left behind the bass. You may not have that punch. You may not have that fun. But overall, you have something more real and close to the will of the artist. Think about it. I recommend the KOEL and I’m glad to have found a brand that provides a non-mainstream sound signature.