Posted by Mark in Ohio on January 10, 2002 at 13:19:44:
In Reply to: Re: How long are they? posted by Alex C on January 09, 2002 at 23:18:48:
Also, be aware that the 32' pedal organ pipe fundamental is the same as the "pedal C" on the ~16' CC tuba!
The ~16' CC Tuba actually functions as a 32' pipe, because it is "stopped" at one end by our chops. As a waveguide, from a physics standpoint, all brass instruments produce their overtones based upon a fundamental length that is actually double the tubing length.
The changes in air pressure that produce tuba sound make a round trip from the bell, to your chops, and back out to the bell.
The vibrating lips simply sympathetically excite the resonances of the waveguide, at a point that will always be at the null(exactly 1/2 or a multiple thereof) of a given fundamental wave length.
Mark "Sure that Matt W. or Rick D. would explain it a lot better" Mazak