Acoustic analysis and tuning of cylindrical membranophones

This thesis scientifically investigates the setup and tuning of cylindrical membranophones as musical instruments. To date there has been very little quantitative analysis of drum tuning with respect to performance sound, studio recording and music production. Digital signal analysis has been used to quantify a number of acoustic related factors to drum setup and tuning. This is concerned with the evaluation of a drum's free vibration once excitation has occurred. Novel analysis of membranophone response is performed with respect to tuning an 'equalised drumhead'. Such analysis has not previously been performed on cylindrical drums with two heads. The findings show that it is indeed possible to tune a drum to a chosen, uniform frequency response and to a quantified accuracy. With reference to previous, non-scientific literature, the fundamental frequency of each drum in the modern drum kit is shown for the first time to be objectively tunable to correspond to a musical pitch. The research also investigates the role of the resonant head in tuning cylindrical drums. Unique analysis of the interaction between the two membranes shows for the first time that the ratios of the modal frequencies present in a drum sound are not fixed and can be manipulated to more desirable ratios. The fundamental frequently present is shown to be the same for both batter and resonant heads due to the strong coupling effect of the (01) modes. Furthermore the current research shows how this ability to manipulate the frequencies present in the drum can be extended to the drum kit as a whole and how the envelope profile of cylindrical drums with two heads can be manipulated via tuning and damping. This research therefore provides an original contribution to the knowledge of drum tuning for both scientific and musical purposes.