If I could get you guys to give your opinions on each, that'd be great. I just bought the 7506 b/c I'd heard so much about it, but the guy at Guitar Center recommended the ATH-M40's. I went w/what I had heard about, but should I go back and exchange this 7506? I'm going to college tomorrow so I wanted some headphones to listen to while I track guitars (through AmpliTube............) and listen to music late at night. So I will mainly be using these headphones for tracking and listening to music. I'm bringing a stereo w/me, so I'll do most of the mixing on there and hten just take my mixes everywhere and try 'em out. So that's what I'm looking for in a set of headphones...did I make the right choice? Thanks, Rohan p.s. I don't particularly want to mix on these.