BRAINWAVZ KOEL REVIEW: All about the mid range.



SOUND: 7/10
DESIGN: 8/10
VALUE: 7/10

After having review the dual balanced B200 and quad B400, its time to give a try to the single balanced armature earphones from Brainwavz: the KOEL

The question is : can it cover whole frequencies range perfectly? The answer is : not exactly. While everything is there, there will be some compromise in sound, especially in bass region, making the Koel a mid centric earphones with plenty of richness to share.

Brainwavz use there famous 3D printer to make a particular housing, bigger than B200, and this is must likely to give a more ergonomic fit and perhaps expand the soundstage.

Now, let’s see in this review if a single armature can compete with other sub-100$ earphones without sounding too anemic.

Disclaimer : I wanna thank Brainwavz for sending me this review sample. As a no BS reviewer, i will keep objective my subjective hearing as well as a very important factor for me : price value.


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UNBOXING experience is always rewarding with Brainwavz and that even if I have to struggle to take off the cardboard around the fancy box. Once its done (this time I have to call the firefighter to help me take it off) we have a generous amount of accessories, especially for this price. One good quality cable, great quality portective case, foams tips and lot of silicone tips. Yep, Brainwavz really put lot of effort in product presentation and needed accesories. I admit that including 2 cables like with B200 or B400 will surely make them go bankrup for exagerated generosity so I can deal with that (anyway, I never use mic on cable, as I prefer getting brain cancer from my phone)

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CONSTRUCTION is well, hum, well, hum. To be honnest, i’m not sure about this plastic housing, perhaps the 3D printer they use isn’t up to date? Technology evolve so fast, I can imagine Brainwavz investing in super expensive 3D printer 2 years ago and nowadays we find better quality. Can’t say, but to me the look is rough, and quite DIY project style. Some part aren’t well polish and there a strange mix of opacity and transparence that puzzle me. As well, one of mmcx connector is a little loose in the housing, so quality check is to blame here. For the look did I personaly care? Nope : its in my ears and I don’t give a damn about what people think. But i’m worry about overall durability. Can’t lie (as other reviewers do so smoothly). Cable is of good standard quality and did not affect sound rendering negatively (proof that its a nice cable).

DESIGN is quite nice tough, wich is why in first place Brainwavz use 3D printer. Housing is ultra light and slip in my ears naturally. Still, its strangely bigger than what I expected due to B200 being very small, but I think Brainwavz take note of people saying the B200 have a too organic form that can be slippy and hard to take off the ears.



So, i’m the kind to listen to music the LOUD way, wich make me fall in an infernal circle of wanting to always listening louder. Lately, I change my habit and listen less loud, wich is still….too much for the Koel I think. This is important to take this aspect in consideration for my review.

Overall impressions aren’t negative at all, its just when distortion occur that i became very annoy and the very problem is either with too bassy music or too complex over crownded with instrument music. The brainwavz Koel is really impressive for a single balanced, it can cover about 100hz to 15khz I would say (that’s very must likely innacurate!). Mid range is where the magic happen, it have great detailed timbre while maintening a good transparency that permit above average imaging. Bass in another hand is perhaps punchy and still realist, but lack thickness and impact and feel thin, especially in sub where it can litteraly disappear. Treble is well extended and natural, little dry but quite snappy for a single balanced.

SOUNDSTAGE is average and have more deepnest than widness, I consider the presentation as intimate and in your head.

BASS is roll off and lack weight and impact, it sound rather thin and dry especially under 150hz. Mid bass save the whole game with an impressively fast presentation that have good punch due to extra timbre emphasis. The punch isn’t feel, its heard. But even if dry, this do not mean bass do not have any body to it, I just underline this because lot of people are basshead without knowing it, so, this is problematic for sure. Basshead run away : FAST!

MID range is quite delicious and will really impress people listening to folk signer or any type of signers that aren’t sit on big bass. It’s just enough bright to give a realist and detailed timbre. Tonality is right too and can transient response is fast. There good attack and decay. For vocal, female signer sound more natural than male signer due to lower end bass drop. Whole sound of Koel is slightly dry with good transparency, it help for overall agility of imaging. Vocal are intimate too, not super wide. I do not hear any important sibilance.

TREBLE is agile and deliver a quite detailed presentation. I feel its quite roll off around 10khz tough, but with extra micro details in upper range. Percussion sometime feel in background in a quite neutral way, wich is a plus in some sens, but there extra brilliance with high pitch metallic hit hat. Acoustic guitar lack grip and fine definition too. Inconsistancy of treble make the Koel very genre specific.

AMPING neew some power for those, and i find the Koel benifit from powerfull DAP or portable amp, it will expand soundstage and give more articulate imaging. However, bass can became more distort if ampin is too powerfull of not very clean.


SUB : 5.5/10

MID BASS : 7/10

MIDS : 8.5/10

TREBLE : 7.5/10

TIMBRE : 8/10


ATTACK : 8/10

KOEL VS E3000 :

Soundstage of is wider and more around your head than Koel more intimate and transparent one, wich have slightly more deepness to it even if it feel more in your head.

BASS of E3000 is more extended, thicker and more impactfull, it have better fuller timbre and more energy to it, but can slightly warm the lower mids. Koel have drastic bass roll off and feel thin and dry in this region, mid bass is more fowards but lack body wich make the impact quite light.

MID RANGE of E3000 is warmer and fuller, but more recessed than mid centric Koel. With Koel we have wide vocal presentation that feel more present than other frequencies range, while it is very appreciate for signers, it tend to stole the show of rest of instrumental and affect proper imaging. Mid range of E3000 is more linear and richer in the sens it show everything in 1khz-8khz range without discrimination and feel overall more balanced and natural than Koel. As well, male vocal of E3000 sound fuller due to better bass response.

TREBLE extend further with Koel, wich make them brighter too, but not in an unpleasant agressive way. Anyway, even if E3000 have rolled off upper treble, timbre sound richer and overall tonality more natural than dryier Koel, that while giving more micro details and sparkle, feel less well balanced and more distorted when lot of instrument mix up.

Construction of Koel is average, mmcx connection looking fragile as well as rough 3D printed housing. E3000 look more expensive than it cost, for Koel, its the opposite even if it have detachable cable.


Koel VS B200 :


SOUNDSTAGE of B200 is clearly superior in widht and dept and feel more spacious and airy than the more ‘’in your head’’ and intimate spaciality of B200.

BASS of both this earphones isn’t very impressive, both being rolled off and quite dry, still B200 have more punch and better separation than Koel.

MID range is similar again, both of this iem being quite mid centric wich make them feel balanced, the B200 have little more body and widness, making the vocal floating instead of being stock in middle of instrumental like the Koel.

TREBLE is similar as well, giving detailed but dry texture to timbre and having distortion problem time to time at too high volume. Due to better imaging of B200, there more decay and sparkle to highs, while the Koel are crisp and fowards.

Both construction use same plastic, but B200 is smaller and will fit more easily any ears.

VS BQEYZ BQ3 (55$) :

SOUNDSTAGE of KOEL is airier and about same wide of BQ3, but less holographic, deep and tall.

BASS of BQ3 is more extended, have more weight and resolution and better attack than drier and thinner sounding Koel.

MIDS of BQ3 have more body but are less texutured and presence than more mid centric Koel, wich have wider vocal presentation as well as brighter more detailed mid range.

TREBLE of Koel is brighter but less extended than BQ3, but it feel more balanced and linear, and while BQ3 have more brilliance in upper range, Koel have more sparkle in mid treble. Anyway, layering of BQ3 is from another league and level of microdetails is better too.

CONSTRUCTION of Koel look fragile and kinda ugly, while the BQ3 look sturdy and beautifull. Koel is less comfortable and can have problem to fit properly due to strange housing shape.



For a single armature iem, I can’t say the Koel are bad at all.

These are very detailed and cohesive sounding earphones with marvelously rich midrange.

Still, I would suggest to buy the B200 over these for a more immersive sound experience with bigger soundstage and more extended dynamic in both end.

As well, the construction and quality check is a little problematic for earphones in this price range if it was 20$ I would not even talk about it, but at 70$ we need to be more severe.

All in all, if we only take sound aspect, the Koel are very capable earphones and quite impressive if we give credit to single balanced armature aspect, it sure isn’t an all arounder, but have a particular finess and agility that will benifit instrumental music and all type of acoustic instruments. If you listen at high volume or are an addict to bass performance, the Koel isn’t for you, but if you want to hear your favorite (female) signer in an rich intimate space, the Koel will sure impress you.

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