Author: Bob Phillips
Date: 2006-09-13 15:04
As a technologist, I'd be very skeptical that any benefit could come from an asymettrical mouthpiece. In my evolving mental model of clarinet sound generation, I see a coupled acoustic system consisting of the player's mouth throat and lungs, the reed, and the instrument.
The reed vibrates while being restrained by the player's embochure and while interacting with the two (player and horn) resonant systems. The reed vibration is certainly non-linear --it may slap against the mouthpiece rather than vibrating simply like the strings on a guitar.
If the reed doesn't actually hit the tip rail of the mouthpiece, it still changes its resonanant frequency continuously as it wraps around the facing of the mouthpiece. Recall the physics class demonstration where the prof plucks a meter stick and then pulls the vibrating "reed" across the edge of the bench --shortening it and making a system for that executes a glissando. The shorter stick vibrates faster.
It is clear that the reed needs to have a high natural frequency and substantial damping to make the overall system settle down quickly when the player changes fingering.
Some of the wonderful harmonics present in the sound of a clarinet come from the overtones of the horn itself, and some (much) comes from the non-linearity of the reed's vibration. Some of this non-linearity can be influenced by the player by preloading the reed with the lower lip to adjust the average amount of wrap over the facing curve.
The facing asymmetry will have at least two effects: the two sides of the reed with change natural frequency at different rates as the reed wraps over the lay, and the reed will twist around its long axis. The twisting might even pull the edges of the reed off of the rails.
Certainly, all of these additional modes will add "richness" to the sound --by adding harmonic content, but I can't imagine that being beneficial --or consistent between different reeds.
One study found, however, that the torsional mode of clarinet reed vibration contributed strongly to the overall sound of the instrument. The torsional vibration adds twisting (rail to rail) motion to the "flapping" of the reed. The torsional vibration would probably be encouraged by rail asymmetry.
Won't the torsional vibration mode be harder for the player to control?
Bob Phillips
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The Clarinet BBoard
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