The air has to escape somewhere, and if it is around the thin inserted sheet metal, there may arise a harmonica effect. I rather would keep the corks, but shave them as much as possible without letting the mute touch the inside of the stack. Maybe a few thin corks should be added further up to stabilize the seating of the mute. The corks should not be shaved so much that the mute goes stuffy.the elephant wrote:Klaus, I have often thought about buying a used H&B Symphonic aluminum mute (the large one) for a 4/4 tuba, removing the corks and re-corking it like a practice mute, then cutting out about half of the cap and replacing it with very thin metal (like .5mm aluminum). Think this would work?
Mutes have their complex shape for a purpose: structural integrity. Cutting a hole might ruin that stability. If the said mute has an indentation on the top plane, then I would cut it into 6, 8, or more sections, radial pizza-style. Then the triangles may be doubled back on the inside without touching the mute inside. The edges of the octagon (or whatever) then may be compressed by means of pliers. That will give you a stable area to rivet the thin metal to the mute. Maybe hammered brass or copper may give the most alive sound.
This outline of course will need to be adapted to real life.
Klaus





