Introduction:
Since
Brainwavz’ BA-only models have followed a simple numeric naming
scheme where the first number indicated the number of drivers used
per side, one could have assumed that their latest single-BA model
would be called “B125” or “B175”, but nope, it is called
“Koel”
instead.
It’s
not a secret that the original, unfortunately discontinued B200 is
among my all-time favourite in-ears regardless of price (my ranking
in terms of preference of the B series goes B200 > B100 > B400
= B150 > B200 v2), and it’s nice to see another new BA-only
in-ear offering, especially in the low-ish-priced single-BA territory.
Packaging, included Accessories & Stuff:
Basically the same accessories and design that was introduced with the B400 – simple, white and sleek.
When it comes to the shells, the Koel’s are surprisingly big, which is quite a surprise given that they wouldn’t have to. The newly integrated hook should help with stability in one’s ears.
Personally I really like the way the Koel looks and how it appears visually different from the other B series in-ears (both the ones with the old injection-moulded and the newer ones with 3D-printed shells).
Build/3D-printing quality has visually improved since Brainwavz switched from injection-moulded to 3D-printed shells and the Koel looks and feels like a quality product.
Packaging, included Accessories & Stuff:
Basically the same accessories and design that was introduced with the B400 – simple, white and sleek.
When it comes to the shells, the Koel’s are surprisingly big, which is quite a surprise given that they wouldn’t have to. The newly integrated hook should help with stability in one’s ears.
Personally I really like the way the Koel looks and how it appears visually different from the other B series in-ears (both the ones with the old injection-moulded and the newer ones with 3D-printed shells).
Build/3D-printing quality has visually improved since Brainwavz switched from injection-moulded to 3D-printed shells and the Koel looks and feels like a quality product.
Comfort and Fit:
I personally own quite a few in-ears and headphones and have additional access to probably just as many, and can say that the Koel fits me very well. Due to its size though, people with small ears might face problems despite the ergonomic design.
Sound:
Used ear tips: only largest included silicone tips.
Used driving gear: only low impedance DAPs, DACs and Amps.
Tonality:
The Koel continues the way that was introduced with the B200 v2 – it’s an in-ear with nicely executed mids and highs but one large flaw which is its poor bass extension present during listening to music, sine sweeps and also when performing acoustic measurements.
What one can hear is that Brainwavz aimed to create an in-ear that heads into a balanced, natural direction without much colouration, and while they succeeded in the mids, highs and everything down to 200 Hz, the level below 200 Hz is unfortunately too little to be considered even flat/neutral in the bass: the Koel has one disease which is its quite poor bass extension.
- - -
Lower/starting central mids are just slightly lifted compared to a flat in-ear such as Etymotic’s ER-4S/ER4SR or the still largely neutral UERM or Fostex TE-02, introducing just a bit more warmth to vocals between around 200 and 700 Hz. Thid does help somewhat to compensate for the lack of flat extension of the actual bass, but only to a certain degree.
Generally the mids have got great timbre with upper mids taking just a slight step back with female and bright male vocalists still retaining most of their sparkle (the Koel is no in-ear with a dark tuning) wherefore they don’t fall into the “relaxed”/dark category yet but aren’t offensive in the upper mids either.
Going up, the middle highs take a step back around 5 kHz and create some relaxation here, something that is quite common among most in-ears, while the upper highs are back to about neutral levels again wherefore the treble balance is executed just right with cymbals sounding only just a tad alienated while the rest of the instruments in the higher range appear realistic, which is not often the case in this price range.
Extension past 10 kHz is nice up to 14 kHz although subtle air is somewhat less present due to the single-BA’s natural limitation up here.
Below 200 Hz, which is where its roll-off starts, is where the Koel’s flaw lies, as its bass is gradually declining, and while the root is still represented as it should be and with neutral tendencies, the upper bass already shows less-than-neutral punch, followed by the midbass that is even less present, and the sub-bass that is under-represented as well. It’s not that the low bass isn’t audible at all, however as its quantity decreases the deeper it goes and since the upper bass is already slightly less than neutral in quantity, the sub-bass and midbass are perceived as too light, even when compared to those other in-ears mentioned a little further above that are tuned for a quite neutral, flat bass response.
- - -
For those who are looking for a rather neutral in-ear without much colouration below the $100 mark, there used to be several models during the years, however pretty much all of them have been discontinued by now, and haven’t received a successor. I’m sure there may be some, probably hidden somewhere/not as popular/not by widely-known manufacturers, but I’m not really aware of them.
That the Koel rolls off too early and too strongly in the lows for in-ear standards, well even for full-sized-headphone-standards, is a shame, and it seems to portray the B100’s/150’s antipole in the lows, as in the areas where they had too much quantity (from a neutral perspective), the Koel has too little. It feels like Brainwavz got the general timbre right but forgot the importance of linearly extending bass. And that they have definitely proven that they can do it (R3, M3, B2 (I don’t have the latter though)).
Resolution:
Resolution in the mids and highs is good for a single-BA in-ear at this price although not fully at Etymotic-levels.
Overall, the Koel’s mids feel a bit better separated than the highs, however since the Koel lacks the B100’s and B150’s lower midrange fullness, what’s happening in the music seems to be masked less with busier tracks and the Koel remains cleaner in comparison.
The bass, at least what is actually there of it, is tight, but that’s no surprise since the Koel is not pushing the limits of the single BA driver.
Soundstage:
… is ultimately somewhat wider than deep to me. Wider than the B1X0s’, but with less spatial depth in comparison. It appears cohesive and not flat though since the Z-axis still has around 50-60% of the width’s expansion.
Instrument placement/separation are around average for the class of single-BA in-ears around that price range and neither too blurry nor ultra precise – overall the spatiality appears realistic but just doesn’t have the precision of some other in-ears.
Conclusion:
The Koel offers great shell design and build quality but ultimately lacks in the tuning department, at least when it comes to the execution of the bass (pleasant mids and highs coupled with rather lacking/less-than-neutral bass extension). Therefore, from my point of view, it is a failure, just like the B200 v2.