Sennheiser PX-100-II On-ear Stereo Headphone review

This is a long-existing headphone with a well-deserved reputation for sound quality -vs- size and cost, yet being open-back it is severely restricted in where it can be used. I had this in the closet for years due to the earpads being worn out, and taking it out a few days ago the earpads had actually turned to dust. So I ordered some new earpads and re-acquainted myself with the sound, which really surprised me. A big part of the surprise I figure is probably that the open-back design doesn't create resonance-based colorations the way most small closed portables do.

http://www.hifiheadphones.co.uk/forum/showthread.php?t=4199