I am looking at a couple of headphones, I am not sure what I should be looking at. My budget is $400 USD. I like the Beyerdynamic DT 990.\n\nI listen to a variety of music and I was thinking how can I tell while shopping online for a pair which would be good for what genre of music? How can I tell the frequency of headphones, and for what genre of music? Which headphones can produce good bass? Which headphones have a perfect reproduction of natural instruments or in-game sounds for gaming, etc... What should I be looking at?