École Nationale Supérieure de
Techniques Avancées

Résumé

The soundboard plays a critical part in the sound of a piano, and although makers have general principles for its design, they do not have precise control on how every parameter will affect the final result. Therefore, it is essential to set up a precise model of it in order to draw links between its various characteristics and the quality of the resulting tone. In this paper, after a brief reminder of some generalities about the piano, measurements that were performed on 19th century instruments are analyzed, so as to draw the principal frequencies of the vibration modes of their soundboards. Then, a plate model for finite element analysis is detailed, and is used to run computations of modes on four different soundboard designs. After noting that the correlation between simulations and experience can only be relevant in lower frequencies because of a high mode overlap, they are compared together. The results seem encouraging, however, the model does not yet take into account some important parameters, namely, the force applied by the strings on the soundboard. For that reason, the thorough comparisons will be made as a next step of the project, along with work on other elements of the piano model. According to the encountered difficulties, some suggestions are given for future tasks, notably about the plate model, which does not seem sufficient to represent precisely the complex structure of the soundboard.