Bass drum - Construction
The bass drum consists of a cylindrical soundbox (shell) made of wood (occasionally of plywood or metal) and two heads stretched across the open ends of the shell.
As on the snare drum the two heads are stretched over a flesh hoop, which has a slightly larger diameter than the shell. A counter hoop placed on the flesh hoop is attached with screws or threaded rods to the tensioning brackets which are mounted on the shell. The heads are tightened by screws (10–16 depending on the size of the instrument) which allow the heads to be precisely tensioned.
In the orchestra calf heads are generally used. Donkey skin is equally suitable but harder to come by. Smaller drums such as those played in pop, rock and military music (especially those used by marching bands in the open air) normally have weather-proof plastic heads. The batter head is usually somewhat thicker than the resonating head and both should be made of the same material.
In the orchestra the bass drum is suspended on leather or rubber straps (very occasionally on wires) in a special, usually round frame in such a way that it can swing freely and be placed at any angle or playing position.