I'm in the market for headphones around the $400 range. Right now my main options are the Beyerdynamic T90s, the AKG K702 65th Anniversary, the AKG K712, the Mr. Speakers Mad Dog, and the Sennheiser HD600-HD650. I've been researching deeply and can't really come up with a good decision as far as finding headphone that can be good for critical listening and proficiently handling the genres I listen to. I do a lot of production and mixing and mastering so something with an honest transparent sound would be ideal. I listen to jazz (instrumental), classical, electronic, ambient, r&b, and rock. Anything that could point me in some direction would be great. I'm driving these with a HiFiMAN ef2a, but if I purchase something sub $400, I'll consider buying an additional amp. Again any information/reference will help.