Pros: never harsh sounding, no sibilance, easy to listen to, wide soundstage
Cons: bass rolls off, not very detailed, a bit muddy, dark sounding, overpriced
Firstly, this headphone is the prime example of something I'd love to hate.
I did like the HD595 as a non fatiguing headphone... and yeah the HD598 is better. But that ugly design and MAP restriction left a sour taste.
I'm still saddened they didn't switch to a 1/8 inch connector as most devices use that nowadays. Another problem is the impedance varies among the frequency greatly, especially in the mid-bass. Don't plug these into some receivers, they will get really muddy.
It sounds like the HD595 with better clarity, and more treble. But again much better can be found for the money.
Supposedly Sennheiser fixed the build quality issues, but we'll see...