Can anyone tell me why a cornet (and presumably trumpet) mouthpiece has to have such a small bore just beyond the cup? (I am genuinely intrigued!) Just after the cup, there is a narrow orifice, then the mouthpiece widens again within the shank until the bore is that of the leadpipe (more or less).
I am having serious problems with a “strangled feeling” in the throat. Today I got my “magnifying glass” out. Without the mouthpiece, I could blow (all passive, honest!) through the instrument very easily. Blowing through the mouthpiece is a lot harder. Blowing through the mouthpiece and instrument is, unsurprisingly, harder still. What makes it hard is the orifice just downstream from the mouthpiece cup. (I believe flow rate changes with the square of the bore, so this makes a big difference.) Why does the bore have to be so much smaller just beyond the cup than at the (instrument) end of the mouthpiece? What’s the physics behind this?
I think I am currently trying to force way too much air through the instrument, so I’m putting in enormous effort to build up pressure and the throat just closes. Think I understand the problem and will experiment further, but I’m now wondering whether there is actually a mechanical solution, or at least a mechanical change which may help.