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Brainwavz Koel

  1. Johnny Mac
    Brainwavz Audio KOEL Realview.
    Written by Johnny Mac
    Published Jul 21, 2019
    Pros - Clear midrange, non-fatiguing highs, included Comply tips creates great seal and isolation.
    Cons - Stock cable could be better, rather long body accounting for some discomfort
    Communication is an essential component of a community and while we have our own way of communicating via different sorts of languages, other species also have their own particular form of communication. Birds for example communicate with each other by constructing either a sequence of drawn-out melodic or short bursting noises to convey whatever message they want to relay.

    If you haven’t known it yet, the birds’ reference was in relation to the IEM that we will be realviewing now from Brainwavz Audio, a company that started way back 2008 and has already appeared multiple times on Audio Realviews thanks to their collection of ear pads options for various headphones. That particular IEM is the Brainwavz Audio KOEL, marketed as an “affordable audio excellence” set and priced at $69.50 (On sale for $39.50 as of 17/07/19). You can check the KOEL out in the official Brainwavz Audio website.

    The KOEL is spec’d out with a single balanced armature driver with a 16Hz to 22kHz Frequency Response, 30 Ohm Impedance and a 105 dB Sensitivity. Will the Brainwavz KOEL sing and chirp as it’s marketed to be or will it just squeal and shriek like it isn’t supposed to be, let’s chime in to find out.

    Packaging and Build Quality
    The KOEL came in a much nicer packaging than I’ve been accustomed to seeing from a Brainwavz package, it now comes in a rectangular semi-glossy white sleeve with the KOEL name upfront as well as the highlight Comply ear tips and 24-month warranty that it comes with. Removing this sleeve reveals the gray matte flap box and the vibrant mix of colors that covers the foam cutouts that protect the textured hard case with a red zipper lining for that trademark Brainwavz appeal. Here’s a list of the included accessories that the KOEL comes with:

    • 6x Sets of Silicone Ear Tips (S M L)
    • Set of Comply Foam Tips T-100
    • Shirt Clip
    • Velcro Cable Tie
    • Instruction Manual
    • Warranty Card (12 month warranty)
    The KOEL is made entirely of 3D-printed resin that either comes in the “Stay Frosty” or “Cosmic Black” colorways. The “Stay Frosty” colorway was provided for the realview and the main difference that it has against the “Cosmic Black” is that it has the Brainwavz branding in the faceplate whereas the other does not. Its shape resembles that of the famous Jelly Belly candies with a slight lip on the lower portion to provide added seal and isolation. It feels a bit uncomfortable upon initial use which made me tinker with the IEMs position on my ears longer than usual to get a decent seal and comfortable fit. The underside of the KOEL IEMs features a discreet L and R markings along with a single vent and a gold-plated MMCX connection. The nozzle is short with a narrow bore and a pronounce lip that worked great with tip rolling and securing the Comply T-100 foam tips as well as the included silicone ear tips.
    The KOEL’s stock cable has no official specifications but is built solid, the black rubber insulation clearly hides a braided cable inside that has moderate tension making the cable a bit tangle resistant but retains folds easier as well and good thing there is a Velcro cable tie for that cable storage solution. The gold-plated 3.5mm plug comes in a 45° angle with great strain relief, same goes for the Y-split which now has a Brainwavz logo ending in a gold-plated male MMCX connector with an over-ear memory guide. There was minimal microphonic noise to be observed as well.
    Tonality and Isolation
    The KOEL sound signature diverges from the Stay Frosty colorway that was sent over for realview. The KOEL exhibited an overall warm sound with an emphasis on the midrange, an aspect that was somewhat showcased even in their BLU-300 Bluetooth IEM. I tried hard to use the silicone ear tips that was included and although I usually prefer silicone ear tips over full foams, the packaged Comply T-100 was just too hard to resist on being paired with the KOEL, it also gave the best seal and isolation among the ear tips that the KOEL came with. I used the Sony A46HN music player and the Sony CAS-1 via Foobar v1.4/MSI GF62-8RE for the duration of the realview outputting various FLAC files which would be mentioned along the realview.

    Coming in with a slow burn, Jamiroquai’s Night Out in the Jungle in 16/44 FLAC was used for the low-end test of the KOEL. The sub bass lingers long with a soft thump and a slight touch of power and control. Bass drops that starts dropping on the earlier part of the track are borderline thin sounding, just a heave and those that seek a powerful and impactful low-end will feel displeased. The KOEL won’t go chasing bassheads for their approval with its presentation.

    The KOEL’s midrange is its sweet spot. Michael Learns to Rock’s Sleeping Child in 16/44 FLAC glides through with ease and clarity. The lower midrange delivery has great body and has notable coherence with the midrange male vocals, coming off as articulate and engaging. The upper midrange performance was rendered in a breathy manner with a smooth extension and lively ambience outcome. The balance of complimenting the midrange frequencies allows the KOEL to handle acoustic tracks with ease and the genre that this particular set will gladly handle all day.

    Jamiroquai came high and about with the KOEL’s higher frequency test with their Carla single in 16/44 FLAC and the KOEL/Jamiroquai collaboration created a less than crisp outcome. There is not much to grasp with the treble hits and was rendered soft and easy to the ears, this allowed for a loose and non-fatiguing experience. While there is great clarity and definition on the different instrumental notes and hits, a gamble on a tasty treble bite would have been welcome. Let me sneak in an inherent KOEL build discomfort as the rather elongated shell body created minor discomfort which balances out the would be longer listening session the KOEL’s highs would have permitted.

    Soundstage and Imaging
    Less than intimate, less than spacious, more on here and now. The KOEL’s soundstage is a good blend of intimacy and expansive, left to right and right to left panning is observable although not exceptional. Easy to deduce that the soundstage won’t be the reason you’d be picking up the KOEL. Imaging though was another story, there is great detail retrieval and instrumental presence is on a high, they can be easily placed here and there. Layering is a much more notable aspect on the KOEL than width and expansion.

    The Brainwavz KOEL takes on an approach that is supposed to showcase a birds overall qualities and it indeed sang with its midrange performance and chirped its way with its complete accessory set. It isn't all bells and whistles though with the KOEL, a birds squeal was represented with its rather mediocre stock cable while the shrieks was represented by the minor build discomfort which when taking into account that ear shapes and sizes varies, is a matter of argument. The KOEL's midrange emphasized sound signature was done cleanly and while it once again suffers the usual BA-driven dilemma of a rather lack-luster low-end, it still creates an engaging and calming musical encounter. (At the $39.50 price as of 17/07/19, the KOEL is more than worthy of being checked out)
  2. NymPHONOmaniac
    The attractive Mirage of Mid-range
    Written by NymPHONOmaniac
    Published Apr 6, 2019
    Pros - Good clarity, great mid range, good attack, good details, generous accessories
    Cons - Bass weakness, can distort at high volume, thin timbre, average soundstage, so so construction.


    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.


    P1011252.JPG P1011253.JPG
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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)

    P1011261.JPG P1011260.JPG P1011259.JPG P1011258.JPG

    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.

    SOUND :


    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

    SOUNDSTAGE : 6.5/10

    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.
      ValSilva likes this.
  3. Otto Motor
    Brainwavz Koel: The Great Pretender
    Written by Otto Motor
    Published Mar 17, 2019
    Pros - Great midrange and detail resolution; smooth sound.
    Cons - Bass is light and ergonomics may not be for everyone; hard to drive; lacks dynamics.
    For the complete picture, you find this review plus a complimentary second one on "Audio Reviews".



    A bit over a year ago, I read an article on the latest balanced armature earphones from Brainwavz and ordered the now discontinued B100. It had been lauded by headflux.de for its tuning details: for its good cohesion, slight warmth, relaxed sound, and particularly for his lack of a grossly exaggerated bass (rather rare in this price segment at the time). Apart from that, it is small and comfortable. I ordered them and found all to be true. A few days ago, I used them on a Transatlantic flight for watching movies and listening to music, and I still like them a lot.

    I also purchased the now discontinued B200 v1. which is optically indistinguishable from the B100 but it sounds a bit rounder at the low end and has a better resolution. In fact, I find the B200 v1, so well tuned that I claim it is the almost perfect earphone for me minus the resolution of the >$1000 models. I also tested the slightly ”fatter” sounding B400, which is technically even better but has a different tuning: it is warmer through a prominent bass hump and may have a broader appeal. All Brainwavz models belong to the best my collection can offer and I was therefore keen on trying out the KOEL, which follows the B400 and revised B200 in that it features a 3-D printed shell.


    Driver: Single Balanced Armature

    Rated Impedance: 30 Ω

    Frequency Range: 16 Hz ~ 22 kHz

    Sensitivity: 105 dB at 1 mW

    Cable: Detachable

    Cable Connector: MMCX

    Plug: 3.5 mm, Gold plated

    Warranty: 24 months

    Price: $69.50


    The content is Brainwavz standard: earpieces, six pairs of silicone tips, one pair of Comply foam tips, standard cable, cable tie, shirt clip, user guide, and a sturdy hard case. Note: three pairs of tips (S,M,L) should have narrow bores and the other three wide bores according to the included manual; however all tips had the same narrow bores.



    Brainwavz claims that the shells are “state of the art liquid resin 3D printed”. Their general build is the same as the current B200 and B400 models. The translucent housings are optically reminiscent of cough lozenges and have received a mixed reception: some find them downmarket and others a novelty. To me they are barely adequate considering the competition's fine CNC-machined housings. The detachable MMCX cable is also standard Brainwavz and of good, proven quality. I like the connector angled at 45°.


    I was initially struggling with the shallow insertion depth paired with the light bass (see tonality). I frequently thought I could achieve a better seal and therefore more bass (extension) by pushing the tips deeper into my ear canals…thereby only pushing the earpieces senselessly against my outer ear generating discomfort – but I had always reached a good seal before doing so. In the end I got used to the ergonomics, and comfort and isolation are actually quite good. Nevertheless do I question the size of the earpieces that only host a single balanced armature driver. I am not sure whether this is a requirement of the 3-D printer or a gimmick to make the KOEL equally flashy as the numerous multi-driver competitors in its price class. The discontinued B100/150/200 v1. all had the same tiny and light shells which make them still favourites in my daily earphone choices.


    I used my iphone SE and the largest included eartips – which are identical to the ones included in all B-series models. The Koel needs some power – it is not the easiest earphone to drive.


    The big picture: The Koel is a slightly warm and smooth sounding earphone, characterized by a mature and refined midrange and an overly light bass and treble. It lacks major flaws such as unwanted peaks above the lower midrange but also dynamics. And it is hard to drive. The tuning is characterized by an inverted U-shape of the frequency response curve, which is unusual and therefore interesting in this price range. The Koel is tuned to sound more expensive than its class peers – and Brainwavz did a decent job with this. Its most outstanding characteristics is its excellent detail resolution. Midrange and resolution are a step up from the discontinued Brainwavz B100.

    The nitty gritty: Yes, the midrange is the shining star of the Koel. Voices are clear and well defined, and they are reasonably intimate but never overwhelming. They are not the thickest but that is in most cases not needed in the context of bass and treble. The midrange is emphasized by a wide but shallow soundstage, the sonic equivalent of a wide-screen movie…the image is stretched in the horizontal with a linear frequency response across the upper bass and lower midrange. This midrange also provides for a very pleasant timbre and an enjoyable overall image. The little peak at 3 kHz, similar to the B200 v1., helps shape the vocals, which shows the good quality of the driver.

    The bass is nicely controlled with a realistic decay, but way to subtle and light and not well enough extended for my taste. It starts rolling off at 200 Hz and more dramatically so at below 100 Hz. This removes both dynamics and depth from the soundstage for the benefit of the vocals, which somewhat make up for it. As a result, the low end lacks slam and punch and registers as "below neutral".

    The roll-off at the upper end starts already in the upper midrange at just above 3 kHz, and a mini-peak at 14 kHz adds sparkle and fake clarity and resolution. This early rolloff is similar to the praised B400. The Koel renders high piano notes reasonably well, although they could be a bit more forward. I also found some cymbals deserved a bit more volume and a slower decay. I take it the roll-offs at either end are the price to pay for “tickling” this terrific midrange out of a single BA driver.

    What I found outstanding was the Koel’s detail resolution, separation, and layering. Typically, budget single-driver earphones have problems with dense instrumentations such as a symphony orchestra, which can result in a congested midrange. Not so the Koel which mastered classical ensembles quite well.

    I was working with two pairs of the Koel and each of them had a pronounced channel imbalance in that each right channel was lacking 3-5 dB compared to each left channel between 20 Hz and 3.5 kHz. I repeated the measurements multiple times and Biodegraded remeasured the first pair on his rig -- and arrived at the same result. Considering our similar experience with three units of the B400 I wonder whether this is a systematic production issue. It is in no case acceptable and should be fixed instantly.

    JK's frequency response of the first pair of Koels.

    JK's frequency response of the second pair of Koels.

    And whereas all of the above may be grey theory, the Koel performed well with most of my test songs.

    Queen’s Bohemian Rhapsody live at Live Aid Wembley was rendered with a good sense of space; you feel you are there. This was hard to achieve with other budget earphones.

    Impressive was the vocal separation between the King’s Singers and Albrecht Mayer’s oboe reproduction in Humperdinck’s “Abends wenn ich schlafen geh” (from the opera “Hänsel und Gretel”). Most of my earphones, independent of price, have problems with this, not so the Koel.

    Louis Spohr’s nonet in F, Op. 31, confirmed the great detail resolution, layering, and instrument separation as well as the timbre of natural instruments.

    Toto’s “Africa” is a good test for a bloated bass, and “99” has a built-in filter for identifying a shouty upper midrange. The Koel mastered both very well.

    David Byrne’s hard to reproduce “everyday is a miracle (live)” was finally bringing the Koel to it limits: Byrne’s voice could have been somewhat denser and the chorus revealed a bottleneck (instrument crowding) in the upper midrange, which is handled smoother by more expensive models.

    But any music that required some punch and energy from the low end such as by the Pixies or Metallica came across as much too polite for my taste. BTO's "Four Wheel Drive", a gritty piece of hard rock representing the famous "Winnipeg sound" with Garnet amps and Randy Bachman's Gretsch guitar was being refined to créme mousse lacking any pizzaz.


    The Koel shines in some aspects but completely fails in others. It excels by its cohesive however little dynamic sound generated by its single balanced-armature driver. Nevertheless, its sound is not balanced in that particularly the low end suffers greatly from the lack of life. The Koel does a good job with classical or vocal music but may not reproduce rock music convincingly for many. The Koel also fails to take ergonomic advantage by not featuring a substantially smaller shell than their driver-loaded competitors. With the Koel, you also get an earful, literally. I am missing the B100/150 design in this respect.

    In summary, with the Koel, Brainwavz have refined and moved their budget BA segment into line with their higher-end models such as the B200 and B400. However this step forward was accompanied by at least one step back. The ergonomically better but technically less capable B100 may have had a less sophisticated midrange but it had the right dose of punch and depth above a robust low end -- something that is crucial for everyday listening. On the other hand, Brainwavz have done a clever job by offering an earphone that essentially has no competitor in its class as it sounds unique. It is a pretender in that it mimics more expensive earphones – and it does it well while not bing a universal earphone for everyone.


    The two review units were provided by Brainwavz as part of their Koel marketing campaign. The fast communication with Brainwavz is appreciated. The sole purpose of this review was to independently test the Koel’s technical and practical capabilities. Following this review, I returned the two units to Brainwavz for their own analysis on 2019-03-27.

    I don't like the points scheme I am obliged to use. The hesitantly chosen 3.5 stars do not consider the channel imbalance.

    About my measurements

    Tonal preference and testing practice

    Test tracks

  4. B9Scrambler
    Brainwavz KOEL: You'd be cuckoo not to enjoy this!
    Written by B9Scrambler
    Published Feb 16, 2019
    Pros - Gorgeous mid-range and overall tuning balance - Isolation - Extras
    Cons - Sub-bass roll-off - Nub on base of earphone might get uncomfortable for those with smaller ears

    Today we're checking out the new single armature earphone from Brainwavz, the KOEL.

    At the beginning of 2017, Brainwavz decided to revisit balanced armatures with their new B-Series earphones. The single driver B100 was my favourite of the the two I had heard at the time (B100 and B150), completely winning me over with a crisp, detailed signature that didn't skimp on the low end extension. Add to that a hilariously low price, a tiny, low profile housing, and the best preformed ear guides on the market. The B100 was nothing but win.

    Like the B100, the KOEL features a single balanced armature as it's driving force. Taking queues from the B200 and B400, the housing is 3D printed using a high quality liquid resin, though with a much more unique shape this time around. MMCX replaces the fixed cable system of the older B-Series models giving users the ability to swap to a different cable should they so choose.

    Is the KOEL worthy of being the only single BA model in Brainwavz's current lineup now that the B100 and B150 are no longer available? Let's find out.


    A thank you to Marlon with Brainwavz for sending over a sample of the KOEL for review. The thoughts within this review are my own opinions and do not represent Brainwavz or any other entity. At the time of writing, the KOEL was retailing for 69.50 USD. You can check it out here: https://www.brainwavzaudio.com/products/koel-balanced-armature-earphones


    The KOEL is surprisingly lax when it comes to pairing it with various sources, so, I just picked my favorites and went from there. It spent most of it's time with the Shanling M0 or Radsone Earstudio ES100 paired via Bluetooth to my LG G6, LDAC codec engaged. It spent less time with the ES100 acting as an external amp for my Asus FX53V laptop.

    Personal Preferences:

    I listen primarily to various EDM sub-genres (liquid drum and bass, breakbeat, drumstep, etc.), hip hop, and classic rock. My preferences for earphone tuning are quite relaxed and as such their is no one signature I look for. The HiFiMAN RE800, Brainwavz B400, and Massdrop x MeeAudio Planamic are examples of earphones with wildly varied signatures that are enjoyable for different reasons. I generally listen at very low volumes, so keep this in mind when perusing my thoughts on how an earphone sounds.

    • Driver: Single balanced armature
    • Impedance: 30ohms
    • Sensitivity: 105db @ 1mW
    • Frequency Range: 16Hz - 22kHz
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    Packaging and Accessories:

    I really like the packaging Brainwavz has created for their armature series. It has a very premium feel to it compared to much of the competition. A big part of this is because it shares a number of qualities with the packaging of the significantly more expensive HEM series of earphones from Optoma Nuforce.

    On the front of the cream white exterior sheath in a clean, contrasting black font. you find the usual Brainwavz branding and model information. In addition, there are notifications for the inclusion of Compy foam tips and Brainwavz's generous 24 month warranty. The sides of the sheath are completely blank while the back contains some trademark info, the Brainwavz logo, and a number of images to coincide with the contents.

    Sliding off the sheath reveals a matte grey box with 'Brainwavz' pressed into the magnetically seal flap and '24 month warranty' pressed into the main panel. Flipping back the flap you find the inner left panels contain the Brainwavz mission statement and a short description of what the warranty covers. In the enclosure on the right you find one of Brainwavz's outstanding black and red elongated hard shell cases set within a foam insert. Resting on top of the foam, surrounding the case, is a paper insert with a psychedelic colour scheme thanking you for your purchase. Within the case resides the KOEL and accessories. In all you get:
    • KOEL earphones
    • MMCX 3.5mm cable
    • Shirt clip
    • Velcro cable tie
    • Comply T-100 foam tips (m)
    • Single flange silicone tips (s/m/l x2)
    • Manual and 24 month warranty card
    Overall a great accessory kit. You get one of the best cases in the business, quality ear tips, and some potentially useful little extras like the shirt clip and velcro strap. No complaints here. Plus, you can't argue with a 24 month warranty which shows that Brainwavz is confident in the quality of their products.

    Build, Comfort, and Isolation:

    Like it's bigger brothers the B200 and B400, the KOEL features 3D printed resin housings with a low profile, over ear design. A unique aspect of this jellybean like design is a small protrusion out the base of each ear piece that nestles down into the tragus and antitragus of your outer ear, essentially serving to lock the KOEL in place. I found this design to work quite well and was able to wear it comfortably for a few hours at a time. Those with smaller ears might experience hot spots, but we shall see once they get into more hands.

    The construction itself is quite nice. Unlike my early B400, the KOEL's frosty shells are smoothed and polished on the exterior. There are no sharp edges or misaligned parts. Neatly integrated into the spine of each ear piece rests an MMCX port. It protrudes ever so slightly which should allow you to fit a wide variety of after market cables should you be keen on swapping out the included one. The Brainwavz logo is printed into the inside of the main face of the body, with L/R labels printed on the inner face next to a tiny vent. Not only is this functional and pretty cool looking, but it completely negates problems like labels rubbing off, something that is usually an issue on earphones where that info is painted on. The nozzle is smaller than average as is usually the case with armature based earphones. At around 4mm wide with a small ring to hold the tips on, you're not going to be able to swap to something like JVC Spiral Dot tips without making an adapter. The KOEL has a small Knowles-style filter fitted into the tip of the nozzle which is great for not only protecting the driver inside, but also for easy cleaning should you get dirt or wax on it.

    The cable will be familiar to fans of the brand. It features multiple twisted strands coated by a tough, matte black sheath. While it does tend to retain bends out of the box and is a bit springy, this cable has shown me time and again that it is tough as nails. Plus, microphonics are pretty minimal, strain relief is prominent, and you get the same style of angled ear guides that were first introduced with the B100 and B150. I love the shape of these guides as they work very, very well. In fact, I do my best to mimic it as closely as possible on earphones with memory wire that actually works. The MMCX plugs on this cable are great too. While the cable can spin in place, which I know some of you out there dislike, the connection is strong enough to prevent that from happening during regular use. I'm sure as the product ages and after numerous disconnects it will loosen up, but out of the box the plugs are nice and tight, but not so tight they're difficult to detach.

    Isolation surprised me at how good it was. Given the fairly shallow insertion depth and vent, I was expecting isolation to be pretty average but it's not. Typing on my laptop without any music playing, you can just barely hear key strokes. Once you've got music going, they are completely gone. When taking my nightly walk through the city, I was forced to leave one ear free so I could hear traffic. Tossing on the included Comply tips just ups the isolation to even more impressive levels.

    IMG_5916.JPG IMG_5919.JPG IMG_5920.JPG


    The KOEL has a well-rounded signature for a single, full-range armature. It's not too dark, nor too bright, nor too mid-centric, instead finding itself playing a quality balancing act.

    Treble is clean and tight with excellent control and good extension. I didn't notice any of the early roll off common to the driver format. Emphasis resides mainly in the lower treble helping with clarity and resolution but limiting sparkle and shimmer on cymbals and chimes, as noticed on “Pure Narcotic” by Porcupine Tree. I tend to prefer this over upper treble emphasis as it generally proves less harsh and fatiguing over longer listening sessions.

    The KOEL's mid-range is refreshingly neutral to my ears, sitting in perfect harmony with the rest of the signature. Male vocals are dense and textured without coming across veiled or smoothed over. Aesop Rock's “Blood Sandwich” shows off the KOEL's mastery of sibilance, and that it can hush the discomfort such a quality can cause. The female vocalist on Massive Attack's “Teardrop” sounds sweet and innocent and it captures the slight breathiness of her performance perfectly. The piano chords that dot the background sound powerful enough and accurate, with plenty of texture to match. This is an amazing mid-range in my opinion.

    While I certainly wouldn't say the KOEL stumbles in the low end, it is the weakest part of the presentation. Going back to “Teardrop”, the trademark deep bass note that opens the track is just barely reproduced. The KOEL's low end is more suited to something like “Crime of the Century” by Supertramp where the drum slaps that kick in around 2:21 have impact and presence, and the low, low note entering at 2:44 has a satisfying reverb to it. These aren't basshead earphones, that's for sure. If you are more keen on texture and speed and don't listen to music that requires deep bass, you'll likely be quite pleased.

    Imaging and sound stage are quite good for a single armature. In the closing moments of Aesop Rock's “Kirby”, he repeats advice from his therapist; “I don't know, maybe get a kitten”. The statement clearly and smoothly shifts just off centre left and into the distance, then does the same in the right channel, repeats the cycle once more, then meets in the middle and fades forward as the song closes out. The KOEL handles this movement very well. Layering and separation are rock solid too with the KOEL able to make heads and tails of the confusion that is the last few minutes of improvised jazz on King Crimson's “Starless and Bible Black”.

    IMG_5922.JPG IMG_5927.JPG IMG_5932.JPG

    Select Comparisons (volumes matched with Dayton iMM-6):

    Brainwavz B100/B150 (discontinued): The KOEL's bass doesn't extend quite as well as the B100 and instead falls right in line with the B150. Focus is on the mid and upper-bass with little in the way of sub-bass presence. The B100's treble is more prominent with additional upper treble that gives it a bit more sparkle than the KOEL. Again, the KOEL's treble emphasis is right in line with the B150, though with the clarity of the B100. The KOEL's mid-range shares a warm, lush presentation with the B150, but with the detail of the B100, and sets the listener further back from the action than either of the B models. We've got a 'sitting in Row 1 versus Row 4' kinda thing going one. Sound stage on the KOEL bests both older B models, though I hear the the KOEL and B100 going head-to-head in terms of imaging accuracy, layering, and separation. Overall the KOEL sounds like it takes the best of the B100 and B150, then merges it into one product. The only thing I end up missing after going back and forth between them is the B100's low end extension.

    I was lucky to be one of the first to review the B100, and as such my review sample is a unique, pre-production model with 3D printed shells. While the basic design was final, it was certainly a little rough around the edges. My B150 was a product model and looked the part with it's glossy, piano black finish, a higher quality fixed cable that is actually the same as the one on the KOEL, and improved fit of the constituent parts. Still, comparing the B100 to the KOEL is neat since you can see how Brainwavz improved and refined their printing process, enough to go from using it only for prototypes to making retail ready products.

    That said, I do think the build of the older B-Series models is nicer overall since they were made using more traditional techniques. But, that also comes with limitations. If there is a design flaw to be addressed or an improvement Brainwavz wants to roll in, applying it is more of an ordeal. By printing their own shells, Brainwavz can easily make mid-production improvements to the product. The B400 is a prime example of this. The nozzle on the original version was long and slim, just like on the B150, but brittle. It was later updated to be thicker and more robust, something that would have been much tougher to address with the B100 and B150.

    EarNiNE EN120 (79.00 USD): The KOEL comes across smoother and more laid back than the EN120 with a less vibrant, more neutral-leaning signature. The EN120 has more vibrant, detailed treble with a mid-range that is physically set more forward within the sound stage. The EN120's mids do less to reduce sibilance and can get a bit sizzly where the KOEL remains calm. However, they do display that somewhat breathy, almost raspy presentation shared by other earphones in the EarNiNE lineup that is unique to their in-house designed armatures. I really quite like that quality since it gives the EN120 a distinctive character. Bass on the EN120 seems to dip off a little later and has more mid-bass punch and slightly more texture. Sound stage on the KOEL is much larger with similar imaging performance. Layering and separation on the KOEL are superior. While I love the distinctive qualities of EarNiNE's custom armatures, the EN120 doesn't display the same level of refinement in it's signature and I'd rather step up to the KOEL.

    The EN120's stainless steel, barrel-shaped housings feel more premium and feature flawless fit and finish. It has a light, flexible braided cable that is outstanding in my experience, but is also fixed to the housing. That'll be a deal-breaker for some. Comfort is pretty even in my ears, but the EN120's traditional shape is small and more flexible since it permits cable up or down wear.

    FiiO FA1 (99.00 USD): The FA1 and KOEL are both 3D printed earphones with single armatures and MMCX equipped removable cables, though the FA1 comes in a full 30 USD more expensive. The FA1 is slightly more treble forward with additional energy in the upper treble regions. While not quite as refined, the FA1's treble gives chimes and cymbals more sheen and in general sounds more exciting. The KOEL's mid-range isn't as forward, either in emphasis or stage placement, but it is warmer, fuller in body, smoother, more natural, and just as detailed and crisp. Bass on the FA1 sees a slight bump in emphasis and extension to a slightly greater depth, though it still doesn't rumble like something with a dedicate low-range armature, such as the KZ BA10. KOEL still has an edge in impact and texture. Raw sound stage size goes to the KOEL as it is able to toss effects further into the distance, however, the FA1 is able to bring sounds in closer and as such is the better performer with intimate vocals. Imaging, layering and separation are pretty much on par. Overall, I think the KOEL is more enjoyable and a slightly better performer.

    In terms of build, it's clear the FA1's extra 30 USD can be found there. As much as I like Brainwavz's improvements to their 3D printing process, and appreciate the unique and comfortable designs they have come up with, there is a rawness to their shells and over construction not present in the FA1. The fairly common (see Kinera H3 and Idun, Tenhz P4 Pro, and TRN IM1 for an idea of the FA1's shape), custom-like housings seem to be crafted with a more matured process, from the smoother surfaces, to the more well-defined nozzle, to the stylish face plate. The FA1 also has a more impressive cable given it is VERY similar in look and feel to what Campfire Audio included with the Polaris. The FA1 has a premium air to it that the KOEL just can't match.

    Final Thoughts:

    At the start of this review I asked if the KOEL was worthy of carrying the mantle of the only single-armature model in Brainwavz's lineup. I think the answer is yes. The new housing design looks nice and feels great to wear. The addition of removable cables is a huge plus that many wanted from the B100 and B150. Add to that a sound signature that pulls from earlier models to create a veritable “best of” that is more versatile than either the B100 or B150 were as solo products, and you've got yourself a quality earphone. The only thing I'm missing from the KOEL is the B100's sub-bass, but I'm happy to waive that for the amazing mid-range performance few earphones in this price range can match.

    If you're in the market for a new armature-based daily driver, you can't go wrong in giving the KOEL a shot. It's a fantastic new addition to Brainwavz's balanced armature lineup and a worthy replacement for the B100 and B150.

    Thanks for reading!

    - B9Scrambler

    ***** ***** ***** ***** *****​

    Some Test Tunes:

    Aesop Rock – The Impossible Kid (Album)
    Hail Mary Mallon – Are You Going to Eat That? (Album)
    King Crimson – Lark’s Tongues in Aspic (Album)
    King Crimson – Starless and Bible Black (Track)
    Supertramp – Crime of the Century (Album)
    Infected Mushroom – Legend of the Black Shawarma (Album)
    Gorillaz – Plastic Beach (Album)
    Massive Attack – Mezzanine (Album)
    Fleetwood Mac – Rumors (Album)
    Run the Jewels – Run the Jewels (Album)
    The Prodigy – The Day is My Enemy (Album)
    Tobacco – F****d Up Friends (Album)
    Felt – Felt 2 (A Tribute to Lisa Bonet) (Album)
    Michael Jackson – Thriller (Album)
    The Crystal Method – Grace (feat. LeAnn Rimes) (Track)
    Jidenna – Long Live the Chief (Track)
    Skrillex – Ragga Bomb (Track)
    Big Grams – Run for Your Life (Track)
    Funkadelic – Maggot Brain (Track)
    Aesop Rock – Fishtales (Track)
      Dsnuts likes this.
  5. thatBeatsguy
    Pretty Koel
    Written by thatBeatsguy
    Published Jan 1, 2019
    Pros - Lean, midrange-forward but mostly balanced sound. Unique and durable build.
    Cons - Nubs become uncomfortable after a while (even more so for smaller ears). Cable is a bit short. Bass distorts at higher volumes.

    Brainwavz has been hard at work over the past year, having released the HM100 headphones, the BLU-300 Bluetooth earphones, and the Zeta budget earphones over the past 12 months. But we are reviewing none of those today – instead, we'll be taking a look at their latest release, the Koel. Priced at 60 dollars, these earphones are meant to be an entry point into Brainwavz' acclaimed balanced armature line. Given their reasonable price point, will they be a solid gift to give this holiday season? Let's find out.

    TL;DR: If you take the time to look past its shortcomings, the Brainwavz Koel with its durable build and balanced, versatile sound, will serve to be a reliable friend for any budding audiophile.

    (Full disclosure: Brainwavz sent me a unit of the Koel free of charge in exchange for my honest opinion on this review, with no obligation to explicitly promote their website or their products. The earphones were tested for about two weeks before the publish date of this review. Although I will try to describe the Koel in a way that can apply to you, this review is still based on my own personal experience and will not be exactly the same as yours.)


    Right off the bat, the Koel scores points for its perfectly rectangular packaging – just the right shape for easy gift wrapping. Jokes aside though, the outside of the box is simple, with not too many details to speak of besides an embossed logo and "24-month warranty" on the front. Inside you get the standard Brainwavz accessory package – a cable tie, shirt clip, earphone case, six pairs of eartips in three sizes, and a pair of Comply foam eartips.


    The earphones themselves, however, are a different story. Like Brainwavz' other offerings in their balanced armature earphone line, the housings of the Koel are crafted using what they call liquid resin 3D printing. A few minutes of research tells me that the process works by solidifying liquid resin layer by layer to create a defined shape. This, Brainwavz says, allows them to create shapes that could otherwise not be achieved by traditional 3D printing. As far as I can tell, they have definitely succeeded on that front. The clear plastic resin makes the Koel a treat to look at, with a housing shape that is quite unlike anything I've reviewed before.


    The Koel also impresses in terms of build quality. The housings feel solid and well put together, and the resin 3D printing process ensures that there are no rough edges that can be detected. The cable, which uses much of the same components as those found in Brainwavz' catalogue, is lightweight but not very confidence-inspiring. Despite that, Brainwavz modified this cable to be removable and therefore replaceable, using the industry-standard MMCX connector. This means you won't run out of replacement options should the cable eventually fail, making sure that the Koel will last a very long time.

    Before I even received the Koel in the mail, I have had some concerns about the nubs that stick out of the earphone's main candy-like shape. These concerns were confirmed to an extent, as the nubs created a pressure point on my ears that became annoying after a few minutes of listening, although I managed to get used to the sensation and ignored it after a few days of testing. I do have a hard time imagining the Koel without these nubs, however, as they do serve their purpose of helping to secure the earpieces on your ears, working in conjunction with the heat-formed cable ear hooks. Overall I had no issues with the fit or the comfort, although I suggest that you take your time with them so you get used to the nubs. With the way the Koel sounds, though, I doubt you would have any trouble logging in the hours.


    For an earphone priced at 60 dollars, the Koel stands out among the crowd for its balanced but ultimately midrange-forward sound. Since the Koel uses a single full-ranged balanced armature driver, a weaker bass impact is not too much of a surprise. However, I find it interesting how Brainwavz is embracing this characteristic and taking it even further, unlike other balanced armature earphones like the MEE Audio A151P and even Brainwavz' own B200 that compensate for the thinner low-end by adding more warmth to the overall sound.

    I would like to make clear, however, that midrange-forward is different from midrange-centric, as the Koel is still relatively balanced sound-wise. Sure, the bass takes a few steps back, but it's never out of the picture by any means. As expected of a balanced armature, the Koel's low end lacks the impact and extension more commonly heard in a dynamic driver, but it manages to convincingly reproduce the aggressive moods of heavy EDM styles (see Rogue – Unity, Figure – Must Destroy) without sounding shallow or empty. But as is also expected of a balanced armature, the Koel has a tight, well-controlled bass response that has no trouble speedingx` through recordings with thick basslines, although the drivers do distort quite a bit at higher volumes (see Daft Punk – Giorgio by Moroder, Lose Yourself to Dance).


    The rest of the Koel's frequency response does not suffer from the same issues, however. The midrange is clean, direct, and straight to the point in its delivery (if a bit too forward and fatiguing at times), eschewing a smoother, sweeter tone in favour of a more versatile sound that ultimately helps tick the boxes for a wider range of music styles. Despite that, it still renders vocals with the same sort of conviction that reminds me a bit of the FAD Heaven 2, a fellow balanced armature earphone whose midrange tone I am in love with (see M2U – Yoake no Uta (ft. Dazbee), Masashi Hamauzu – The Yaschas Massif). The treble is noticeably smooth and free of any intense peaks besides one at around 7 kHz that adds to the fatiguing feel I mentioned earlier. The Koel also has a pretty good soundstage helped in part by an airy quality in the midrange and treble, resulting in a head space that never feels cramped, but conversely doesn't feel particularly spacious.

    With all that said, is the Koel the one-for-all gift earphone? I wouldn't really say so for a few reasons. The stock bass distortion stands out as the most glaring issue, which makes them unacceptable for listeners who might want to boost the bass by even a little bit. The stock cable is also a little too short compared to what I've seen from Brainwavz, and although they are replaceable, doing so is not exactly cheap, coming in at about $20 dollars a pop (before discounts) for Brainwavz' own replacement cables. As I've already pointed out earlier, the nubs are also a mild annoyance, which add to the list of what makes the Koel a bit of a standout earphone in my opinion.


    But maybe that's a good thing. Maybe bass distortion at high volumes is a good thing – it might be telling us not to listen to music so loud. Maybe annoying pain on the ears after extended listening sessions is a good thing – it might be telling us to take a short break. Maybe the Koel is all the better for all of the things I dislike about it.

    When I think about it, the Koel is kind of like a friend that you've known for a long time. He has a bunch of flaws, both glaring and subtle, that you are perfectly aware of. And although that may be so, you still consider him your friend and wouldn't trade him for the world. And, from my experience with the Koel, I wouldn't trade it for the world either.

    Packaging, Accessories: 8/10. Standard Brainwavz package. Has everything you need, nothing you don't.

    Design, Build, Microphonics: 8/10. Interesting looks, solid build, good cable (albeit a bit short).

    Fit, Comfort, Isolation: 7/10. Pretty good across the board, but the nubs are annoying after a while.

    Bass: 6.5/10. Lean, tight, and controlled, but distorts quite a bit at higher volumes.

    Midrange: 8.5/10. Clean, direct, and versatile. Can't go wrong with it.

    Treble: 8.5/10. Crisp and clean, although slightly fatiguing.

    Presentation: 8/10. Good all around, but otherwise unremarkable.

    Other Media: 7.5/10. Not sure what's actually exploding, whatever's in the movie or the distortion from the drivers.

    EQ Response: 6.5/10. Bass is arguably its only weak point; too bad you can't boost it without the drivers distorting.

    Value: 8.5/10. Priced quite competitively for its feature set.

    Total: 7.7/10. If you can make it past its flaws, it's a very good IEM that will last you a long time.
      dhruvmeena96 and B9Scrambler like this.