Hey guys; So, tomorrow I am going to go buy some new haedhpones for my MBP as well as XB360. I am buying them used, off of KSL, and I want to figure out a way to test them before I purchase them, using my MBP. Usually, I'd just plug them in and make sure that they work, but these headphones boast 5.1 surround sound and have a microphone. What's the easiest/most efficient way you can recommend to be able to test surround sound, high/low sounds and the microphone? I confess to not being very adept with GarageBand, so I am not sure. Would there be a way to mix my own GarageBand song, maybe 15-20 seconds, that would test these features? Thanks for any/all help!