Analysis and synthesis of bass drum tones
Harvey Fletcher, Irvin G. Bassett · The Journal of the Acoustical Society of America · 1975
Tones from a bass drum were recorded and played repeatedly through a 3-Hz bandpass filter. With each pass, the center frequency of the filter was increased 1 Hz. From this analysis the frequency, intensity, and decay rates of the most prominent components of the tone were determined. A reasonably close relationship was found to exist between these components and the ones predicted from the Bessel functions for a stretched membrane. Up to 200 components have been identified in this manner. These components vary in intensity according to where and how hard the drum is struck. The frequency of the fundamental decreases as the amplitude of vibration of the membrane decreases, finally approaching a constant at low amplitudes. Each of the components has a changing frequency that remains proportional to that of the fundamental. Synthetic drum tones were computed by adding a series of sine waves with frequencies, amplitudes, and decay rates taken from the analysis. Tones thus synthesized were compared with the recording of the real tones. A listening test was performed using 25 subjects. Each was presented a series of 30 tones consisting of three real and three synthetic sounds repeated five times in random sequence. The subjects were asked to decide whether each tone seemed real or synthetic. Overall results for the 25 subjects tested were 56% right.