Measurements and theoretical calculations of timpani modal frequencies and decay times
are made for the cases of no kettle enclosure and kettle enclosures of varying volume. For
the calculations, the timpani membrane is assumed to be ideal and the kettle is assumed to
be a rigid cylinder which is volume equivalent to the actual kettle. A Green function method
is used for calculating the effects of air loading. The calculated modal frequencies and decay
times are generally in good agreement with the experimental measurements. In particular …