弦の高次振動に及ぼす端部剛性の影響

抄録

An electric guitar is composed of a wooden body, a wooden neck, an electromagnetic pickup, 6 steel strings and other electric parts. The electric guitar changes string vibration into an electric signal with the electromagnetic pickup, and the sound is emitted through an amplifier. Usually, high density and high stiffness wood is used for a body material, to prevent vibration transmission from a string to a body. Then, string vibration sustain longer and the sound remains. Also, it is reported that the material of a body influences the quality of the sound. In previous study, vibration energy propagation of two test guitars composed of different body material are observed with experimental SEA, and a strong correlation of vibration propagation characteristics and sound pressure level is reported. To clarify the mechanism more in detail, correlation between frequency characteristics of string vibration and stiffness of edge is discussed in this report. To simplify the discussion, experimental set up only with string and several types of edge (with different stiffness) is built. As a result, correlation between edge vibration and string vibration is clarified by comparing fixed edge, and two elastic edges; string is more excited when vibration of an edge is transmitted and the edge itself less vibrates; frequency characteristics of edge influence on the frequency characteristics of the string; and vibration of string does not influence on frequency characteristics of the edge.