[RockCity]

To Gradofan2: I have the new metallic lining HD600 and the black silk HD650 and their differences were still negligible. I've read your impressions about the damping materials before. I was wondering did you listen to more than one "old" HD650? I've compared the materials against a light and they look equally porous.

 

[FallenAngel]

Even unbalanced, the Beta22 can drive HD600/HD650 much better than a lot of balanced amps

Personally, I prefer both.

HD600 is more forgiving while HD650 will reveal synthesized bass notes and play them exactly as they are - kind of flat sounding bass, not the impact of the real instrument.