Vibrational Modes of a Rabana (Drum)

Abstract

The vibrational modes of a "Virindu" Rabana membrane (of diameter 13 inches), which was driven by a loudspeaker, were studied by using a microphone.The vibrational modes were observed at frequencies below 500Hz. The nodal patterns seen here were slightly different from theoretically expected patterns for an ideal membrane. It was observed that most of the vibrational modes were degenerate. These degeneracies could be due to the non-uniformity of the membrane and the imperfect membrane boundary. However, the observed frequencies were close to that obtained from theory.