Posted by Tom C. on August 26, 2003 at 17:52:54:
In general, theory tells us that the frequency of a tone is controlled by the length of a vibrating column of air and the length of the column is controlled by the length of the pipe it goes through. Now you take a brass instrument, such as a tuba, which has a bell section that starts as a conical tube and turns into a flare at the end.
My question is where does the bell stop influencing the length air column? Is it at the end of the "cone"? The very end of the bell? Somewhere past the bell? There's no way to tell?