Study of Motion of a Bowed Violin String
Joshua Kohut, M. V. Mathews · The Journal of the Acoustical Society of America · 1971
The velocity of a bowed violin string was measured at various points along its length and with various bow positions by placing a magnetic field perpendicular to the string and observing the voltage induced in the string. The string was found to oscillate in a simple triangular pattern described by Helmholtz. At all points on the string, the ratio of flyback time to period of the oscillation equaled the distance from bridge to observation point divided by string length. This equality implies that larger-amplitude vibrations for a given bow speed can be achieved by bowing closer to the bridge. It also implies that the waveform at the bridge has an exceedingly rapid flyback time and hence is rich in high-frequency components which are transmitted to the body of the instrument. Deviations from a triangular waveform were observed. These consist of slight rounding of the corners of the triangle and a superimposed sinusoidal oscillation of small amplitude.