[sjwright]

I'll go one further and assert that in a noisy environment, the Bose QC15 have the absolute best overall sound quality of any headphone I'm aware of. By a very, very long mark.

I had a few very sophisticated sets of expensive headphones (plus a headphone amplifier) and I just don't use them any more. When I don't need to wear headphones, I'll sit down in my theatre room. When I need to wear headphones, it's because I'm in an environment with other noises (office, travel, etc) and the noise cancellation trumps any other cans' refinement.

[stcredzero]

Even Beyerdynamic 770 Pro? I tried active noise canceling in the past, but found the sound ultimately fatiguing. I prefer passive cancellation now, and 10db is a significant amount of isolation.

[sjwright]

Absolutely; the 770 Pro are one of the cans I own (the 80 ohms model). They're exactly the set I reach for when I want to listen at home with privacy.

In a noisy environment though, they just can't compete. Yes, the 770 Pro have excellent passive isolation characteristics, but they do absolutely nothing for low frequencies [0] whereas the QC15 achieves 20db [1]. This makes all the difference in the world when you're trying to escape into music while flying.

I know what you mean about active noise cancelling being fatiguing. I've been lured into noise cancellation before, only to be repelled by the strange feeling of pressure within the ear. I wouldn't have given a moment's consideration to the QC15 had I not been loaned a pair by a friend. I'm not going to say the QC15 are perfect for everyone, but to my ears the pressure phenomenon is pretty much nonexistent. I've worn them for an entire 13 hour flight without a moment's discomfort.

[0] http://www.innerfidelity.com/images/BeyerdynamicDT770.pdf

[1] http://www.innerfidelity.com/images/BoseQuietComfort15.pdf