Acoustics of rototoms
Thomas D. Rossing, Ju-Yong Kwon · The Journal of the Acoustical Society of America · 2000
Rototoms are single-membrane drums that can be quickly tuned by rotating the drum. The sound spectra and modal shapes recorded holographically show membrane modes quite similar to those observed in other drums, such as tom-toms, snare drums, and timpani. The sound is dominated by the fundamental radiated bathe (0,1) mode of vibration. The frequency ratio of the various partials changes with tension over the playing range of each drum, resulting in a changing timbre.