I'm jumping into the world of headphones. I've managed to get an open-box Bayerdynamic A1 amp at a reasonable price, and was getting all excited over the matching T1s that I've just bought when I took them off and realized how much sound they leak. No good chez moi unfortunately. So, what are the best closed-back options? I've heard mixed things about the Beyerdynamic T5p on various forums (despite WHF's endorcement). What else should I be looking at/listening to? Many thanks for the help.