Vibrational mode shapes in Caribbean steelpans Part Ⅱ: cello and bass

摘要

Complementing earlier studies on tenor and double second steel pans, vibrational mode shapes have been studied in cello and bass pans by two well-known pan makers. Normal modes are determined from operating deflection shapes recorded by means of electronic TV holography. Vibrational modes of the various note areas are designated by the number of radial and circumferential nodal lines. Tuners generally tune one mode an octave above the fundamental and, if possible, a third mode is tuned either a 12th or two octaves above the fundamental. Modal shapes in the skirts correspond to standing bending waves propagating around the circumference of the pan. The contributions of skirt vibrations and air cavity resonances to the observed sound spectra are small.