Measuring body vibrations of stringed instruments

Measurements of stringed instruments are used to interpret their vibrational characteristics, notably the input admittance and mode shapes. This talk will demonstrate methods to capture, process, and analyze stringed instrument measurements, focusing on surface vibrations. First, methods of suspending and isolating the instruments are discussed. Next, excitation methods, including the impact hammer and shaker, are demonstrated. Sensors will then be presented to measure the resulting surface vibrations, including accelerometers and laser Doppler vibrometers. Methods to view the mode shapes, including the roving hammer and scanning vibrometer measurements will be discussed. Finally, once the measurements are collected, techniques to post-process and analyze them with mode fitting will be discussed. This presentation will include video demonstrations of the previously mentioned measurement methods as applied to guitars, violins, and other stringed instruments. Best practices and the pros and cons of each method will be discussed.