Guitar making the acousticians taleBernard Richardson
A long-standing research programme at Cardiff University has established the low- and mid-frequency mechanics and acoustics of the classical guitar. Techniques such as holographic interferometry and finite-element analysis have yielded considerable information about the modal characteristics of the instrument and their relationship with the construction and materials of the instrument. Considerable work has also been undertaken to determine the sound-radiation fields associated with these modes, establishing those modes which make the greatest contribution to the radiated energy. Studies of string dynamics (including the interaction with the players fingertip) show how readily the strings energy is coupled to the body and sound field. Our measurements and models allow a relatively small number of measured parameters to be used to predict the sounds radiated by a guitar; these sounds can be used for psychoacoustical tests to gauge those modifications to the guitars structure which are likely to produce perceptible differences in sound quality.
The aim of this paper is to present the key finding of this work in a form accessible for the practical maker and to present simple models which can be used by makers for effective decision making during the construction of an instrument.