EVALUATION OF THE ACOUSTICAL STIFFNESS OF SAXOPHONE REEDS UNDER PLAYING CONDITIONS BY USING THE REACTIVE POWER APPROACH

The dynamics of a saxophone reed has been analyzed by means of the sim plest model-one pure spring-acceptable for frequencies below the reson ance frequency of the reed. As proposed in the context of bowed string dynamics [J. Acoust. Sec. Am. 90, 754-763 (1991)], a reactive power i s defined for the air-column of a saxophone and its reed. When the ins trument sustains a harmonic tone, a balance between those two reactive powers can be established, as a generalization onto a multimodal syst em of the usual condition sin(phi)=0 that a simple oscillator fulfills when it vibrates at its resonance frequency. The stiffness of the ree d can be derived from that condition. Experiments were carried out on a saxophone played by a professional musician. The reed stiffness unde r playing conditions is determined after separate measurements of the input impedance (TMTC method) and of the internal pressure spectrum. R esults are comparable with compliance values measured on isolated reed s by other authors. (C) 1996 Acoustical Society of America.