The hd595 is bassier than the hd558 and hd598? In terms of soundstage, refinement, resolution and imaging are they even close to the hd598s?
As i stated on the last post i dont have enough power to frive open headphones because they simply sound bad straight from an ipod. Butfor 60 euros..... this pair of hd595's plus a cheap amp have the potential to become a great set?
No, the 595 does not hold up to the 558/598 in terms of soundstage and imaging. Resolution and refinement seem like a wash in that the 595 seemed to me to smooth out the details for the sake of refinement. In other words, the 595 has a warmer, meatier, smoother, darker sound than the 558/598.
I have never felt that any of these headphones need more power than an iPod. I suspect that you simply like the bassier punchier sound of the Momentum. I say this based on my audition of the Momentum and 558 side-by-side - I really disliked the Momentum and liked the 558 so much that I bought a pair.