The ZSA is another model released in a flood of high-quality models by KZ. The ZSA are a compact and cheap alternative to their bigger brother, the ZS6. Just like the ZS6, the ZSA suffer from a sharp treble, although it's nowhere near as piercing as the ZS6. The good news is that the ZSA are excellent for those who are looking for cheap earphones with an excellent build quality, deep bass, clear and upfront mids and a crisp and detailed treble.
Although I had some fitting difficulties, other have not experienced it as badly as I did, so it's completely individual. KZ have reached a peak where about every model they release sounds above what you would expect for their price. You can't go wrong with these either.
Despite the similar design to ZS6 and RevoNext QT2, the ZSA have a substantially smaller housings, which makes them suitable for small ears, but they'll have a worse grip for larger ears. Keeping them in depends on how good of a seal you're getting with them.
Lows / Bass
The bass reminds me of the ZSR a lot. The bass is very deep and I can even feel the sub-bass rumble. It's also not that different from the ZST's or ES3's bass response and I would bet that we're dealing with the same dynamic driver, maybe tuned slightly differently. Nevertheless, I have no complains over the bass of KZ earphones in general. It's stable, punchy and just fun-sounding.
Mids / Vocals
The mids are very clear, but seem to have slightly odd positioning. The upper-mids are upfront, while the lower-mids are a bit subdued, and it's more noticeable on male vocals. The upper-mids and treble dominate over the midrange, and it's safe to call this sound signature blatantly V-shaped.
Highs / Treble
Very sharp and crisp with substantial amount of detail, coldish tone and a spiky texture. I wouldn't say that this treble is my prefered kind of treble, but many would appreciate the clarity and delicacy of it.