davewerden

I suspect most euphonium players have never worried about the gap between the end of the mouthpiece shank and the beginning of the instrument's leadpipe. To understand the terminology, the receiver is the two or three inches of tubing attached to the end of the leadpipe. The mouthpiece inserts into the receiver. The gap is hidden underneath the receiver. The drawing below shows this:





Different manufactures may use different sizes and degree of taper ...