The violin bridge-island input filter
Colin E Gough · The Journal of the Acoustical Society of America · 2018
The influence on the acoustics of the violin of the bridge and the island area between the f-holes is demonstrated by treating the body as a thin-walled shell structure. COMSOL finite element software is used as a quasi-experimental tool to identify and understand the coupling of the bridge, island area, offset soundpost, and bassbar to the radiating surfaces of the body shell by varying their properties, often over a wide range. The frequency dependence of the resulting input filter between the vibrating strings and body shell modes is derived using a quasi-statistical averaging approach involving the strong damping of the body shell modes. The bridge-island filter response over the whole playing range of the violin is shown to be strongly dependent on the properties of the bridge, island area, soundpost, and bassbar. Their properties influence both the intensity and tonal balance of the radiated sound and the broad Bridge-Hill feature in the vibro-acoustic response of many fine instruments.