With the headphones on, those large earcups prove to be very comfortable with the soft leatherette-covered surround feeling wonderful against your skin. That said, we'd prefer that the padding were thick enough to fully hold the inner section away from your ears. As it is the inner section touches your ears, thus requiring it to be padded as well. Though this isn't something we could test, and thus vouch for, having padding right over the drivers could degrade sound quality. At least the headband provides plenty of adjustment to ensure that the AC 9050 PH's weight is distributed over the head rather than directly on the tops of your ears.
However, while initially comfortable the closed back design limits the opportunity for air to circulate, leaving you with hot and sweaty ears when worn for more than half an hour. We also found it a minor annoyance that the headband adjustment could be moved so easily, to the point where they seemed to loosen enough to require the occasional refitting when worn for extended periods.
You should be giving your ears a break every hour or two anyway, for the sake of your hearing, so these issues may not concern you too much. Nevertheless, open-back headphones suffer less from these sweat and heat issues and plenty of other headphones hold their fit better.
A rather more positive consequence of the closed-back design is that it blocks out a decent amount of ambient noise. They don't shut out the entire outside world like a good set of in-ear or noise-cancelling headphones but they take the edge off enough that you can listen relatively undisturbed in a busy office or train. What's more, your fellow colleagues or commuters will be blissfully unaware of your tune of choice as these phones leak very little noise.
It's this very sense of isolation that is one possible let down, though. As with most closed-back headphones the sound they produce is very claustrophobic, making it sound like your head is not just in the middle of the orchestra but all the instruments are within inches of your head. Of course, this is an affect that even the best open-back headphones suffer from to some degree as music is predominantly recorded to be used with forward-facing speakers rather than ones sitting either side of your head. This in turn makes the special characteristics all wrong and is why Riyad loves these Sony Personal Field Speaker Headphones so much.
Nevertheless, if you're after a listening experience that is as close as possible to being there yourself (which is often the desired effect when listening to classical, acoustic, and jazz) then there are better options for the money, like the Grado SR60s, say.