I made something like this for my bari several years ago, so why not make one for bass too. This one gives a perfectly in tune low A on my Noblet bass.
I started with a 56oz Coffee Mate Creamer can from Sam's Club or Amazon. It's about 5.5" in diameter and 8.5" long. Just cut off the bottom and attach some weather stripping that extends past the end about 1/4-1/2". The self adhesive isn't quite sticky enough, so I run a bead of super glue to make it stick permanently. I rubbed off all the printing with some acetone (nail polish remover). You could just as easily paint over it if you prefer.
I don't know the inside bell diameter of American or Chinese basses, but the 5.5" + .25" of foam fits very close to the beginning of the flare on my French one.
I can still play low C in tune with the extension in place, but can't play low B natural or Bb of course.
I started with a 56oz Coffee Mate Creamer can from Sam's Club or Amazon. It's about 5.5" in diameter and 8.5" long. Just cut off the bottom and attach some weather stripping that extends past the end about 1/4-1/2". The self adhesive isn't quite sticky enough, so I run a bead of super glue to make it stick permanently. I rubbed off all the printing with some acetone (nail polish remover). You could just as easily paint over it if you prefer.
I don't know the inside bell diameter of American or Chinese basses, but the 5.5" + .25" of foam fits very close to the beginning of the flare on my French one.
I can still play low C in tune with the extension in place, but can't play low B natural or Bb of course.