Membrane Modes
The (0,3) Mode
The ninth mode (0,3), shown below has three circular nodes, but no diameter nodes. The frequency of the (0,3) mode (ideal membrane only – one not affected by air loading) is 3.598 times the frequency of the (0,1) mode. Like the (0,1) and (0,2) modes, the (0,3) mode is excited when the membrane is struck at the center. The sound radiation characteristics of the (0,3) mode are rather complicated. This mode is excited when the membrane is struck at the center radiates energy efficiently, and the sound dies away fairly quickly. As a result, it contributes to the thump sound when a drum is hit at the center, but does not contribute much to the sustained harmonicity or pitch of a drum when hit off-center.
