I've had a number of headphones through here. At the moment, a set of PS500's (with G-cush) are getting the most use.
The hd-650's sound good, but the bass just never quite sounded right. I sold them, but may retry the Senn sound
with a pair of hd-600's. The hd-650's with a bottlehead amp-now there was a combo that got things right.
As always, the headphones are just one part of the system.