acoustical influence of the geometry of a clarinet Bb reed

Date |
Dec 2015
Technologies |

This research attempted to understand the mode of operation of the clarinet, to obtain the waveform of the clarinet and study the reed from the point of view of vibrations. The reed is one of the most important elements that form a clarinet, and its geometry is key to the correct sound production. This study investigates the influence of the reed’s geometry in the clarinet acoustics.

The clarinet is a woodwind instrument that uses a reed to induce vibrations in the air column and make sound. The reed is made out of an elastic material called Arundo Donax, a variety of cane. This reed is attached over the window of the mouthpiece where the clarinetist blows air into the system. As the clarinet is played, a pressure antinode forms in the mouthpiece, which makes the clarinet similar to a pipe closed at one end and open at the other.

Most studies around the clarinet have been focused on the modeling of the clarinet’s reed. However, the effect of the reed geometry on the sound as well as on the tone of the clarinet has not been studied. Therefore, in this work the acoustics in the tube of the clarinet and the influence of the geometry of the reed in its own natural frequency were analyzed. Furthermore, it was verified that a change in natural frequency of the reed linearly affects the frequency perceived by the air, and therefore the note played by the clarinetist.

First a theoretical model (Four-Pole Method) was used to study the acoustic performance of the clarinet. Second, an acoustic model was created and a parametric modal analysis of the reed was carried out. The obtained simulations have been validated by means of experimental data from a real Bb clarinet.