Quote:
Originally Posted by
EinZweiDrei 
if i do get an amp.
lets say fiio e7 without the use of bass enhancement.
how would ad900 compare to hd558.
I actually have both of these to compare. To me the HD558 were warmer with a bit more mid-bass, but for sub-bass the Ad900 went a little lower with more presence. Most won't agree with this, but most don't have Ad900 that have completely broken in pads that fit snug.
This is off memory though, I still have my Ad900 and HD558 though if you want direct.