Experimental and numerical analysis of the effects of depth, diameter, and tension in musical drumhead coupling

The low frequency vibrations of two-headed musical drums are known to couple. However, little is known regarding the factors that determine the degree of coupling at higher frequencies. In this study, the effects that depth, diameter, and head tension have on the tendency of the drumheads to couple are investigated. Commercial finite element software was used to model a wide range of drums and to identify trends of coupling according to these factors. The numerical results were used to guide which parameters should be tested in the lab. Experimentally, two oppositely facing Electronic Speckle-Pattern Interferometry systems were used to optically view the simultaneous vibrations of both heads of a drum. Several snare and tom tom drums with different diameters, depths, and tensions were observed. To closely analyze the effect of drum depth a tom tom was modified so a range of depths from 1.5’’ to 40’’ could be tested while keeping the diameter and tension constant. The optical and numerical data are used to illustrate trends in the coupling of musical drumheads.