Just picked up a silver pair from Apple Store in Glasgow. I originally planned on trying the P3 with a view to getting a pair of portable cans for casual listening on the go. The P3 seemed to fit the bill until I realised how unsatifactory they sounded, and for that matter, the P5 were also underwhelming. The latter pair were much better sounding than the P3 - more refined and tonally accurate, though still not the level of fidelity I wanted. The sound signature is easy on the ear, but clearly not for the 'audiophile' - whatever that means nowadays. So what did I do instead? Buy a pair of these... blind. I haven't heard the HD25s before so I didn't know what to expect either. 48 hours of "burn-in" later, I'm glad to find myself rather satisfied with my purchase. It's been a while since I posted impressions so excuse the disorganised nature of this post - I'm typing what comes first to mind
The Amperior is for the most part a pretty accurate pair of headphones. It gets the timbre of instruments largely spot on... The upper mids though are prominent, which is in itself not an issue unless of course they sound grainy, which they are. It lacks warmth and at times comes across as quite thin. This is particularly evident in the violin sections of orchestral recordings. Maybe it is the fit of the headphone? Well I have tried all manner of repositioning, pressure over the earcups to improve the seal etc to no avail. Thankfully my listening has diversified these days and I don't listening solely to classical symphonic genres. Having said all that, the slight thinness at the upper midrange actually makes certain solo violin recording (solo works and concertos) sound pretty exciting. There's a nice bite and raspness, just like in real life. Listening to those double stops at near the beginning of Brahm's violin concerto is an absolute joy.
Now slightly lower down in the frequency range, the mid/mid-lower range where the bassoons and cellos reside, the Amperior is an absolute delight. With a well-recorded track, there's a good amount of detail here and a weightiness to it. There's not much wrong here. Sadly, the bass and sub-bass may dominate a little too much for classical, often bleeding into the upper ranges. It's reasonably well-controlled, just not as well as say a higher-end pair of cans might handle lower notes. This is by no means a deal-killer as thankfully the degree of "bleeding" is only moderate and certainly bearable, at least for me it is. For other genres like rock, pop, RnB, the bass is sufficient in volume, but maybe not in visceral punch.
All in all, there is pretty decent bass extension, and a meaty bass too. Tonally there's a good balance of bass/mids/highs with a general emphasis on the lower ranges. The highs aren't sibilant at all and there's just enough shimmer to make the high hats sparkle.
The soundstaging is not spectacular. Passable. There is a sense of space and reasonably airy, which also describes the overall presentation. It's not in-your-face like a pair of low-midrange Grados. I can also make out where instruments come from, but again, the imaging is perhaps not pin-sharp like a pair of good electrostats. The attack is in general well defined. Sharp... ish. Decay believable and realistic. For its price range these are all very positive points.
From an ergonomics point of view, these cans are comfortable to wear, although I'm not sure how they'd fare on an 11 hour transatlantic flight. The clamp on the head, whilst not offensive for an hour or two, may prove too much. Isolation is good, too. The build quality is solid. It's a little strange to see such high quality machined metal cups juxtaposed by seemingly cheap plastiky parts, but whatever; the plastic bits look well made. The one thing I'm not happy with is the flimsy interchangeable cable (the bottom half). I'll certainly be replacing that with something more durable for use at home. The one with the controls will remain for use on-the-go.
Anyway. That's all I have time for at the moment. The Amperiors are here to stay and I'm glad I didn't spend the same amount of money on the P5s, while more luxuriously fashioned, have a totally unremarkable sound. Hope this helps any potential buyers who are still sitting on the fence.