I am going to college soon, so I need to choose a good sealed headphone so that I don't annoy my roommate and still listen to loud music. I have been using a Sennheiser HD 650 for a year now and am looking for something new, so I am thinking of buying either the D600 or K550, which I've heard have great sound. But I still don't know if the D600 will have a good enough seal for me to be able to listen to music at medium volume without leakage. I also have an amplifier, and am planning for just desktop use, not portable, if that helps. Thanks!