[lukas2001]

 
 
Quote:

"...I spent a day and a half tweaking..."

 
Did you ever consider 'burning-in' the headphones before you performed any listening tests?
 
I've had my 7506's for a few months and although I can't exactly remember what they sounded like out of the box I do notice a small difference in the sound now versus then.
You're right that they do sound very clear and concise at first listen but the mid-range isn't as bad as you claim and over time it does change character. I personally find most AKG's lacking bass response, and I'm often in studio situations so I'm not trying to say that my rap music sounds flat, and the 7506 is very nice and warm in that department too.
 
I guess everyone has a different ear and maybe I can't hear the same things as you but I hope that you at least let the headphones play for a few days first before trying to judge them.