Differences between cylindrical and conical reed instruments

Abstract

Most investigations on reed instruments have been carried out on clarinet probably because this is the most common reed instrument. However, the extrapolation of the results to conical instruments is risky. The fact that internal clarinet spectrum does not contain even harmonics is not the only difference. For example the transfer function between input and output pressure is very different: this makes a saxophone, for lower notes, much louder than a clarinet. On the other hand, application of linear analysis near the threshold of oscillation to conical reed instruments is limited: because of the inverse bifurcation, small oscillations do not exist for conical reed instruments. This is confirmed by the observation that it is clearly much easier to play pianissimo with a clarinet than with a saxophone or an oboe. The saturation mechanism seems also to be different for conical and cylindrical instruments. On a saxophone the saturation occurs at a lower mouth pressure because of the existence of more than one regime at the fundamental frequency. All these aspects will be discussed with reference to simplified physical models and illustrated by experiments using artificial blowing. [This work has been done in collaboration with C. J. Nederveen, J. Gilbert, and J. Kergomard.]