Adding +3 dB low-shelf filter EQ from 60 Hz and lower solves the subbass problem for me. Low end remains fast and tight BTW.

Hmmm, even AKG K612 produce more potent subbass than my HE400i.

Well, for 249-299 - absolutely! They sound remarkably clean and fast, with decent soundstage and full-bodied midrange.

New HE400i owner here. No bass extension at all, definitely agree with katzolik. So weird for planar! It's like Fang intentionally limited HE400i capabilities after realizing how good HE400i are for the price.

I'm a happy K712 owner and I tend to disagree with the aforementioned statement that AKGs are harsh and bright when not driven properly. iPad mini makes K712 sound more lush and smooth in comparison to Behringer Ultramatch Pro DAC + AMB M3 amp system. Of course iPad loses the competition when it...

Has anyone tried both HiFiMAN HE400i and AKG K712 (or K7XX) with rock and metal? I do have the K712 so I'd like to know if I should swap them for HE400i. Is it worth trading K712's sounstage for solid planar bass with faster detail reproduction? Yes, I'm aware that 400i are considered poor...

Any thoughts on my question above?

Has anyone tried both HiFiMAN HE400i and AKG K712 (or K7XX) with different metal subgenres (black\death preferably)? I do have the K712 so I'd like to know if I should swap them for HE400i. Is it worth trading K712's sounstage for solid planar bass with faster detail reproduction? Yes, I'm aware...

I've sold TH600 recently - highs are too sharp for me. AKG K612 PRO delivered unmatched sound clarity along with inoffensive treble. But thanks to this thread I almost decided to try HE-400S instead of another AKGs (K7XX). Smooth mids and treble, planar bass - I should check it out.

pr1me, thanks a lot! I already have K612 - really love that spacious and detailed sound. But since I listen to metal music it would be great to add some bass weight. K712 or K7XX might become the ones I'm looking for. On the other hand, these headphones have an emphasis on midbass which...

  And what about sound? Which one do you prefer: HE-400S or K712?

All metalheads should definitely check out this thread. HE-560 included. AKG K712 (and probably K7XX) are really strong competitors for HE-400S. 

Seems like first impressions are promising. Treble quality and smoothness are things I'm really worried about. For example, AKG K612 PRO deliver absolutely the best quality treble in their price range. But even pricier Fostex TH600 have a disgusting treble peak which can be so annoying that I've...

Actually TH600 brightness eventually disappears during burn-in. And now it doesn't bother me after I got used to it.

Sargatanas, according to your sonic preferences, Fostex TH600 might disappoint in some ways:   1) You will probably find the mids to be recessed if you're looking for "in your face" headphones.  2) Denon AH-D7100 are simply more bassy cans. But quality wise, TH600 is definitely a winner here...