I didn't expect my KZ ZSX came faster than my BQEYZ Spring 1.
Well, out of the box with my BT20 and spiral dots that i bring along with my tfz no 3, they sounds very good.
First thing i want to check and confirm is tonality. Maybe im 1 of picky person about steely timbre of KZ. And with KZ ZSX i agree with other comments that this ZSX are different from previous KZ. I can say its passable for my criteria of timbre. Not very great or sounds natural/organic, but quite good, well for KZ maybe the best one. On higher notes i still can hear a little bit steely / metallic sounding but just a little.
Sub bass is very good in texture (again for budget chifi class), with deep extension, good amount for me. Mid bass is south of sub bass in quantity. A very very minor to none mid bass bleed.
Bass decay is normal towards slow with nice rumble
Into the mids, mids are not recessed but i would like more forwarded mids (in comparison tfz no 3 and bqeyz kb100 have more forwarded mids). Clarity is good but not great. Lower mids overwhelmed by upper mids. And upper mids on higher notes can be a little shouty at around 3-6khz. Not as bad as previous kz, still safe but in borderline of harshness on high volume (again tuning is good, maybe its just limitation of their BAs or maybe damper is needed) so females voices on higher notes have tendency to be shouty or any solo / main instrument at that frequencies.
Highs is very good. Sparkles and extension are good without fatiguing. ZS10 pro sounds brighter on 8-12khz in comparison. Have a bit glaring but thats minor.
Fit isnt as bad as they looked on photos. Actual unit ismt as big as my imagination. Zs10 regular not pro still bigger i guess. And that weird shield shape shell cover also arent touch your any ear parts at all.
Separation is very good here. Maybe the strongest point of ZSX. They handle complex tracks better than most budget iems. With good details too
Soundstage is wide on ZSX, with some depth and little height. Can be on par with Kanas Pro But imaging is nothing special here, I can hear roughly where the instrument at, but still blurry, not very accurate rendered. Good job on delivering this very good soundstage on plastic/resin shell.
So for the price, they are very very good. Definitely best KZ for me until today. If im forced to only choose 1 KZ only in my collection i wont think long enough and grab the ZSX.
Please remember that was my early impressions out of the box. I have yet to burn in them. I expect tighter bass but maybe on mids and highs parts wont be so much different because they are handled by BAs.