| It's an interesting and complex system. By "system" I mean both the method of tuning, and the fact that each piece of the drum kit resonates with each other piece, and many drums have two heads that resonate with each other; so the entire thing is like one big complex organism.
First, each drum shell has its own resonant frequencies, the pitches where it will sound out the loudest and clearest. If you look inside a DW drum shell you'll see they actually mark each shell with a musical note, that they determined by knocking on it and listening. Each shell may resonate at more than one frequency though.
Next you have the primary (batter) head. It needs to be tightened with exactly even tension all around its perimeter, and you tighten it overall "more" or "less" with the aim of finding a spot where the air moved by the head triggers one of the resonant frequencies of the drum shell. There is always at least one sweet spot; there may be two or more. IOW with one drum you might be able to find (for example) three different pitches where it sounds loud and clear. So then it's up to you to decide which of those frequencies sounds best with the rest of the kit.
Next you have the resonator head. You tune this to reinforce the resonance that's already occurring with the batter head and the shell.
Lastly you have the whole kit as an ensemble to consider. Imagine it as one guitar chord, and just like a chord, each of the drums can sound sweet or dissonant together. In the case of conga drums, they are often tuned in 4ths just like a bass. In the case of a trap kit, it's up to the taste and discretion of the drummer. Usually most trap drummers are just glad to have each drum in tune by itself, and can't be bothered to think about the whole kit. |