The CCA brand is quite new on the market, and it seems to have tight relations with KZ, especially given the similar designs, materials, cables, package contents, etc. Even the balanced armatures CCA used in the C10 model are made by KZ.
As to the sound quality, it's good. If you want a 5-driver pair of earphones for a low price - these can suit you. However, I find the sound to be nothing more than just "good", and there are much better-sounding earphones out there, many of them are significantly cheaper.
Overall good sound quality and separation of detail.
Massive bass response, very suitable for bassheads.
Super loud and easy to drive.
Very comfortable to wear for prolonged listening sessions.
Excellent build quality with an impressive cable, very much like KZ's recent cables.
Very impressive specifications for such a low price.
The bass can sometimes be overwhelming in orchestral and bassline-heavy tracks.
The mids can sometimes be a bit too upfront, along with some harshness and not quite satisfying timbre.
The ear tips slip off the nozzles very easily.
The channel splitting wires are ridiculously long (total cable length is about 133cm, about 10-13cm longer than necessary for portability), the Y split is way lower than necessary, and there is no cinch, making the cable quite dangly and difficult to control. (Despite that, the inline remote isn't too far from the mouth)
The shape of these earphones is common and well-tested. It's rather standard for over-the-ear style earphones and I found it to be very comfortable for prolonged usage. The earphones aren't bulky, so they sit quite flush in the ears.
Lows / Bass
Lows are highly emphasized on these earphones. If electronic music styles are your jam, then these earphones can easily satisfy your needs. However, for some styles the bass, specifically the mid-bass, is just too overdone. As an example, you can try the popular "Moment of Peace" song by Gregorian. The bassline is clearly too trembly. That's just one example out of many, but overall the bass performs quite well.
Mids / Vocals
Although the mids can be a bit too loud at times, they sound quite good. That being said, when I compared them to some really impressive earphones in that price range, with way lower driver count, like YueGuangBaoHe H1 and even the cheaper TIMMKOO C630 (both are dual-driver hybrids and both are manufactured by Estron), the C10 clearly has a harsher sound with darkish coloration. On certain, more complex music genres, the sound can get a bit messy and unsatisfying.
Highs / Treble
Detailed treble with smooth performance, no sudden peaks, no pierce and no sibilance on vocals. Quite impressive implementation, considering the amount of balanced armatures used in these earphones. Despite that, with such amount of balanced armatures, I expected more treble extension and more separation of detail, as it's a bit too dull for my taste. The treble is tonally darkish (mildly), but at least it's not piercing and quite comfortable to my hearing for prolonged listening sessions.