These little suckers are legit hi-fi, as cheap as they are. A bit hot at the top end, but otherwise they sound right.
Ha, joke's on me. I don't remember having the EQ turned on, but it was, and there was a ca. 5.5 dB bass boost dialed in.
Good thing I checked. The E10s always sounded warm to me, that certainly wouldn't have helped. Also, my UE attenuator has apparently developed an intermittent ground connection.
Will have to fix this somehow, not looking forward to that.
First EQ attempts for the ZSX by ear got me to:
low shelf 710 Hz +4.5 dB Q = 0.7
peak 1 kHz +3.0 dB Q = 1.0
high shelf 5250 Hz -4.0 dB Q = 0.7
Might have a smidge too much bass now (no biggie and in fact welcome on public transport), and I think I'm missing a bit in the "air" territory while mid-treble is plenty present enough, but the basic balance seems alright for the time being. I'll have to look up some other EQs from reputable sources to see how they compare.
JFTR, I am generally running with Meier crossfeed on, and since this Clip+ is my "out and about" player the compressor is also enabled (threshold -24 dB, 4:1, soft knee, attack 5 ms, decay 1000 ms).