Hello guys. I have a 5 days my K812 but in my opinion they sounds little too flat and too high. They don't have a power of sound. My source is a Asus Xonar STX and amp AT-HA5000. You think that they will must burn much more longer and they change sound? Or maybe i must change the lane? I wonder of this: http://www.moon-audio.com/fostex-hp-a4.html. Any suggestions? I don't have much money so it must be a budget.