I don't get good results with the AutoEQ presets, I don't know why but a lot of them just sound outright wrong.

I get much better results with Oratory1990's targets, I tend to like Harman for overears and his own target for IEMs.

Try these if you haven't.

AutoEQ is totally algorithmic and I think sometimes gets it wrong, it can be trying to EQ the high treble, or EQing small peaks or dips, based off measurements that may not have them in the same place you have them on your head. A narrow filter applied to a narrow peak just 500Hz off can make things worse rather than better.

Oratory's EQs are checked manually by listening and tweaked by ear. He doesn't try to EQ anything specific over 10kHz or so, just uses broad high shelf filter. I haven't ever heard one that sounded as egregiously wrong as many of the AutoEQ ones do (particularly the IEM ones).

I don't always only EQ to Harman, either, although I do use Oratory1990's Harman target on over-ears more than anything else. I also on some stuff just address specific issues, so things like, add bass shelf, smooth over or remove peaks, etc. And leave the rest of it alone.

One thing Harman does, with headphones like the Arya, is it fills in/brings up the 1-3kHz recess. This pulls in the soundstage as well. HD800S has a recess in the same place, it adds to soundstage. So I often listen to the Arya with just a Harman bass shelf (or sometimes less) and leave the rest as the rest is pretty much fine. Or with the HD800, just bring up the bass to flat, and, bring down the 6kHz peak a little.

IEMs I generally listen to stock, but there are some with specific issues, like add mid-bass to the Dioko / Symphonium Helios, remove the mid-bass bloat and smooth over the pinna gain wonkiness on the Fiio FD5, add treble to the Dunu EST112 or Zen, reduce mid-bass and treble peaks on the Beyerdynamic Xelento. I'm far more likely to just go for correcting specific issues like peaks or not enough / too much mid-bass on IEMs.

EQ isn't just Harman or nothing, and it's certainly not just AutoEQ Harman which frankly sounds crap to me a lot of the time.