Physics-based simulations for assessing the playability of heritage musical instruments : Impact of the soundboard assembly process on its low frequency behavior

Curators of heritage musical instruments are faced with a number of recurring questions concerning the objects in their collection. Can the instrument be played without damaging it? How might it best be restored? Can we understand how and why the instrument evolved in the way it did and the impact of the different steps in its construction? Indeed, the impact of the different steps in the assembly of a musical instrument must be anticipated in order to assess its playability. Curators may question whether the state of internal stress, deliberately introduced by the instrument maker during the assembly process, should be restored after it has relaxed over time. These questions are typically answered through expert judgment. Meanwhile, it may be possible to leverage detailed physics-based models to enrich the decision support in the museum environment. This novel strategy is illustrated in the present study to investigate the importance of the different steps in the assembly process in order to guide the restoration process. In particular, numerical and experimental studies that have been carried out on a facsimile of the soundboard of the Christoph Koch's archlute of 1654 (E.546) with the objective of quantifying the impact of its assembly and gluing processes on the low frequency vibratory behavior. It is shown that a nominal non validated numerical model is able to predict trends, validated via experimental studies, that can be useful in understanding the impact of the assembly process in order to guide future restorative measures.