Price: 70$

Where to buy them:

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.