Hi
Thank you for repying
Yeah I noticed it is wrong what I wrote. Thank you for pointing that out, I was just tired I don't know.
I love the sound my HD555 (modded) and my V3 make. But I don't like the bass heavy-ish sound of my ATH-M50 in comparison. I do like the ATH-M50, don't get me wrong. But I really wish I could get a pair of closed cups that had similar sound like my V3 or HD555. (Or HD600 in your case)
But of course I don't know if that is even possible.
Did you mean flat frequency response, instead of flat soundstage? It's been a while since I heard the HD555, but the AKG K550 is pretty flat, though it's far from perfect. The bass is actually
too flat and the highs have a tendency to sound a little plasticky, at least straight off my phone. I thought it was all just a matter of using the right source and a high-current amp, as it works fine out of the DX100 and X3 with just minor adjustments to the headband to make them fit a bit tighter (for a portable like the K551 version I used on the X3, I'd rather have the light-feeling comfort than the tighter fit) and make the bass sound deeper (from both the compression+seal on the earcups themselves as well as putting the drivers closer to the ears). Then I heard a modded one with some kind of dampening material inside the earcups, and the sound was close to the HD600 - better actually when you consider that you can get loud enough off a smartphone with this without a lot of distortion.
You might want to check out
reviews on the K545 also - I've heard it sounds better than the K550 (maybe even with the headband adjusted for smaller heads). I haven't heard it yet so I'm going by that review and from a local, reliable source (who also owns a K550). If anything, I'd wager the improved bass on the K545 is likely also due to dampening, maybe the earpads also (that linked review says the soundstage is a bit smaller, so
maybe thinner earpads); plus also the possibility that the K550 driver wasn't so well designed. There were off-hand remarks before about it being a slightly modified K701 driver or something stuffed into a closed earcup, although I can't recall if this was confirmed in any way by AKG). From my own listening using the same smartphone vs DAC-HPamp (with that smartphone as a transport) the 701 scales a lot better with the latter set-up over the smartphone than the K550.