ASA 124th Meeting New Orleans 1992 October

3pMU2. Comparison and prediction of modal parameters of a strung and unstrung piano soundboard.

Duane Leggett

Michael W. Miller

Robert D. Celmer

College of Eng., Univ. of Hartford, 200 Bloomfield Ave., West Hartford, CT 06117

The first eight modes of an unstrung Steinway model-K upright piano soundboard were measured by testing both the front and back sides. Strong similarities in the first eight modal frequencies and mode shapes were found even though 40% fewer test points were used on the back side. Using the dynamic modification feature of the STARStruck modal analysis software system, a prediction of modal parameters was performed for the structural features of a strung piano. Comparison of these results to the actual modal frequencies and mode shapes found by testing the back side of a strung piano soundboard will be discussed. [Work supported by Steinway and Sons.]