Interaction of the Clarinet Reed with an Air Column Having a Single Resonance
John Backus · The Journal of the Acoustical Society of America · 1972
A study of the interaction between the reed and air column in the clarinet is underway, using a synthetic clarinet reed in a mouthpiece adapted to accomodate resonant air columns of various kinds. Measurements of the air flow into the reed-mouthpiece combination mounted in an artificial embouchure show the negative resistance characteristic necessary to sustain oscillations in an attached resonant air column; the value of this resistance is varied by changing the gap between the reed tip and the mouthpiece. A system resembling a stretched-out Helmholtz resonator and having a single pronounced resonance was made to oscillate by attaching it to the mouthpiece and blowing on the artificial embouchure. The input impedance of the system at its resonance frequency was measured on an impedance tube, and it was expected that the system would oscillate when this input impedance was approximately equal to the negative resistance of the reed-mouthpiece combination. However, experiments showed that oscillations did not take place until this negative resistance was about half the input impedance. [This work was supported by a grant from the National Science Foundation.]