well IMO its nearly impossible to tune heads the same on both sides. There will be freq interference if they are off even cents. Take the bottom head off, drums sound better, bigger, and cleaner there's no weird freq stuff going on. It makes a huge difference, imagine head mic and bottom mic phase reversed on every tom.... boooommmmm duuuuhhh duuuhhh duuuhhhh boooooooommm, or something like that...
