Sennheiser - HD 820
The new audiophile standard for closed-back headphones:
With these groundbreaking closed dynamic headphones, passionate music lovers can now enjoy their music at an audiophile level wherever they please, at home or on the move.
Featuring unique glass transducer covers that minimize resonances, the concave glass reflects the sound waves from the rear of the transducer to an absorber, which results in minimal resonance. Thus, the sound waves are effectively “gone” like they would be in open headphones.
The HD 820 are not only transparent in looks but are the most transparent-sounding closed headphones in the world, extending the boundaries of what has been achieved in sound reproduction with closed-type headphones up to now.