Re: Drum Tuning iPhone App
The fundamental is the batter head, the entire column of air in the drum, and the reso head moving down in unison when the drum is struck, and continuing to vibrate up and down, in unison, after. So the fundamental has to be the same for both heads, since the reso head can only react to the air movement in the drum.
Theoretically, at least. The presence of a vent hole throws the results off a little, since some of the air column inside the drum ends up breathing in and out.
The overtones are different and indepedent for each head, as they move as a ripple across each head, and don't incite the same movement of the opposite head.