Well...this is embarassing. I was using my LG G7 to listen to the KZ ZAX and I completely forgot about the stupid impedance detection on it. I usually have something over 50ohms plugged in, never had any decent IEMs (monoprice mp80) before which are way less sensitivie than Sennheiser, Beyers, Hifimans
Put a 3.5mm extension on it to trick it into the line out mode, and voila. Much better. Also checked on some other sources, MOTU M4, JDS Atom, etc. and can confirm they're much better now. Bass is still a bit loose and undefined in those low mids, but it's listenable now without EQ and only really shows its ugly head on certain tracks.
The NM2+ looks like a good shout though. I was really tempted to spend more and go for the Starsea, Shouer Tape Pro, or Starfield. Decided to play it a little safer with the KZ to get an idea of fit and tuning. The MP80s I have are not a good standard to start with.
I will likely grab something a bit more high end if some good sales come up over Christmas and keep the ZAX as cheaper, fun, don't care if they **** up IEMs. Working from home has drove me to in ears. Clamp from the 58x and even the Beyers just unbearable for more than an hour, or my ears are sweating no matter what. IEMs a little uncomfy at first but then I forget they're in the rest of the day.
I think maybe the Starsea would pair well with the ZAX since I like classical. Just a little wary of spending a lot of $$$ when you have no idea if the fit will be good or not. It's completely different than on ears, where I can tell from weight, headband style, reviews what the fit will be like.
Cheers