The ZSN isn't so new by now, and yet I find it to be one of KZ's best releases so far. For a rather modest price, you get a great-sounding pair of earphones with superb build quality and probably the best stock cable KZ has included so far. This time, the dumped the built-in memory wire and went for a pre-shaped ear loops, similarly to TRN's cables. It's braided and durable, yet very flexible. Very impressed by this one, and I encourage KZ to keep using that cable.
When it comes to sound, the best pair to compare with is the KZ ED16, and while they are both amazing earphones, the ZSN presents comparably edgier mids and more sibilance, and the bass on these is on the calmer side. It's hard to beat the delicate sound of KZ ED16, especially at the same price point, but the ZSN aren't that far off.
Either way, many ZSN users are huge fans, and I can surely recommend them as well. What would be even nicer is ZSN's cable and build quality with ED16's sound - that would be perfect.
Thanks to their compact and rather ergonomic design, these medium-sized earphones should fit all ear sizes alike. Using appropriate ear tips, I found these earphones very easy to wear for long listening sessions. No pressure points and no sharp edges that would cause discomfort. Well done!
Lows / Bass
While the bass has great quality and warmth, it feels a bit overwhelmed by the upper-mids and treble. I get nice punching bass, even with some sub-bass, while the upper-mids are rather silent, but as soon as those get louder, the bass seems a bit lost behind the high frequencies and the punch gets a bit dry. It's just a balancing issue, and probably can be solved with an equalizer, but just have to point that out.
Mids / Vocals
Very vivid, pronounced and even edgy/shouty at times, given the obvious boost at upper-mids/lower-treble frequencies. For some music styles, especially electronic music with a lot of emphasis around that range, the sound can be a bit fatiguing, so keep the volume level at bay.
Highs / Treble
Very detailed treble, I'll give them that. There isn't a lot of missing detail, you can pretty much hear every microdetail, to a point. However, on higher volume it might be unbearably loud and overwhelm the lower frequencies, especially the bass, and that could make the sound seem chill and thin. That been said, this is a specific issue with specific kinds of music, and as long as you don't go crazy with the volume level, you'll be fine, and you'll sure to enjoy some high quality sound.