I was taught to raise the front of the bass by placing my fingers underneath the hoop and then locking it down at that height. (a half inch.) It not only has to do with the resonance of the drum, it has to do with the angle that the beater strikes the head. Once you attach the pedal, you raise the back of the drum about as high as what you set up front.
When the beater strikes the head, it is parallel to the drum head (see illo 1).
Raise the front too much and the beater will dig into the head (see illo 2).
Too much height in the back and the beater will have to go past 90 degree vertical to strike the head (see illo 3).
Mind your beater angle! Raise the front of the drum only enough to match the amount the pedal raises it in the back. The beater will hit dead vertical (beater will be perfectly parallel to the drum head,) if the drum is set-up right.
I whipped up a graphic in photoshop to illustrate what I'm talking about. It's important stuff to know. Save a lot of expensive heads and grief if you do it right.
[IMG]http://i1143.photobucket.com/albums/n632/PurdieShuffle/illo.jpg[/IMG]
John