Posted by Sven Bring on January 28, 2004 at 06:25:18:
In Reply to: Mouthpiece Tinkering posted by Mr Fixit at Work on January 27, 2004 at 16:38:27:
A brass instrument is a pressure feedback system. The direction of the pressure waves oscillates, and the waves going from the instrument to the lips are as important as the waves going the other way. The surface of the mouthpiece end that is perpendicular to the air stream is an obstacle for the returning wave, and in small bore instruments it can constitute a substantial part of the cross section area. I remember calculating that I could augment the cross section area at the mouthpiece end in a euphonium with about 30% by making the backbore taper to very thin at the shank end. IMHO, this could influence the playing characteristics some.
Sven