THE ASYMMETRIC DESIGN

An analytical/experimental technique called multiple nonlinear regression was used with an orthogonal composite fractional factorial experiment design to model the explicit operation of upper and lower half-cup curvatures and cup depth along with their interaction effects, in order to determine, generally, the optimum cup geometry for extended high range performance. This macro analysis resulted in the predicted asymmetry that is the identifying feature of these mouthpieces. Then to refine the specific cup design, a similar analysis which treated the three characteristic curves (mouthpiece entrance, flow-converging concave curve, and convex throat entrance) as independent variables, for both top and bottom inside cup surfaces, enabled explicit compound curvatures to be generated for those ideal cup shapes that maximized high range. Then, prototypes were made for balancing geometry (cup, backbore and throat size) and tailoring sound, always keeping in mind the application of each model. Additional consideration had to be given to the low (below low C) register, which led to further modification and more prototypes. This is the first time an analysis of this kind has ever been applied to the trumpet mouthpiece. In fact, I believe that these mouthpieces have undergone more analytical scrutiny and are of a more sophisticated design than any other. And the results show it!