Would anyone be familiar with any good 'demonstration' audioclips that can be used to test out and compare headphones, or to completely blow away people who haven't seen the headphone-light with the great audio quality of your cans? Preferrably they'd be downloadable in some lossless audio...

Some time ago I decided to get myself a decent headphone, and the sennheiser hd580 has cought my eye. I didn't know much about headphones and I only today realised that earphones don't work directly on line-outs and mp3 player headphone plugs. I'll need a headphone amp. But when I see the...