Re: Re: Re: Re: Re: Leadpipe Taper


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Posted by Frederick J. Young on April 23, 2001 at 08:47:19:

In Reply to: Re: Re: Re: Re: Leadpipe Taper posted by Chuck(G) on April 22, 2001 at 12:39:50:

There is a proprietary book published by the German government that does exactly what you want. If you visit a German instrument maker, he will graciously show it to you but is prohibited by law to let you copy it.

Given the diameter of the instrument and mouthpieces as a function of position along the length of the instrument I can calculate the frequencies of the open and vaved tones. Then I can make taper alterations to try to fix problems.

With regards to the flatness of the 5th open tone on many tubas something has been done.
If you put a chamber between the end of the mouthpiece and the beginning of the lead pipe backbore, the 5th partial can be adjusted in frequency. The length of the chamber should be about 1 inch. Anything longer or shorter makes that open tone flat. The C. G. Conn Company have a patent on the length of the chamber which you can obtain from the US Patent office complete with curves. Also you shall note that Dillon Co. makes a device that they install on the tuba to allow one to adjust such a chamber. However, they don't say exactly what it is supposed to do. Don Harri of Eastman School has one and he loves to tinker with it.

I'm sorry I can't tell you about something that would be simple as well as useful.



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