Comparisons of theoretical and experimental transverse motion for a plucked, stiff piano string
Jose R. Sanchez, James H. Irwin · The Journal of the Acoustical Society of America · 2001
This work is meant to determine whether central or backward difference approximations in computer simulations more closely approximate reality. The stiff piano string motion is experimentally measured by a real-time analog optical technique that was developed to measure the one-dimensional transverse displacement of a plucked string. The optical technique uses a detector that collects laser light not obstructed by the string. The received light is converted to a voltage, which is related to the string displacement perpendicular to the laser beam. The signal is then filtered and conditioned by external circuitry, digitized by a Mona data acquisition system, and are displayed using Cool Edit Pro. These measurements are then compared to two different finite difference computer simulations. One of the computer simulations uses central differences and the other uses backward differences, both with the appropriate boundary conditions and parameters. The comparison of the experimental data and the computer simulations is comprised of informal listening tests, spectral, and time domain comparisons.