Of course like all of their other headphones, the cable were hooked up to something beneath the display table and connected to a designated iPod Touch. Luckily the Amperior has that odd 2-part cable and I got to listen to it with my source in-person (Sansa Clip Zip + FiiO E7, using no EQ settings and no bass boost on the E7). I must say, I am pretty disappointed with its sound overall. The mids seemed recessed (Sennheiser veil?), the highs were very sibilant to my ears, and the lows were punchy and phat, yet didn't overpower the rest of the sound spectrum; the bass was actually similar in extension and punch to my Sennheiser HD238. Instrument separation was good, but the soundstage was lacking in depth and width (I would not recommend the Amperior for classical music listeners).
I was genuinely surprised to hear the sibilance from the Amperior; and to think DJ's use the HD25-i-ii at loud listening levels? :/ It was quite painful for me to listen to and I'm coming from a "bass light, excessive treble" Shure SRH940. Looking at the Innerfidelity frequency response shows that the Amperior has a wider treble peak, so that might be the reason.
I listened to a variety of music genres (acoustic, alternative rock, Chinese folk, Chinese pop, chiptune, classical crossover, classical, dubstep, electronic, pop, synthpop, symphonic metal) for a good 30 minutes (the employees at Apple didn't seem to care). I don't think I would pay over $200 for them, which puts them on par with the HD25-i-ii's pricing. The isolation and comfort were really good for a supra-aural headphone and that was probably my favourite thing of the Amperior.
^My face when I first heard the Amperior with Chinese folk music