Posted by Frederick J. Young on May 24, 2002 at 16:33:51:
In Reply to: Re: Re: Re: Re: Re: Re: Basses and Contra B. posted by Not rick, but on May 24, 2002 at 09:03:30:
To properly scale any device all of the dimensionless ratios describing the general shape of the device must be preserved. For a brass instrument some of these ratios (bell diameter)/(bore through valves diameter), (mouthpiece diameter)/(mouthpiece back bore diameter), (mouthpiece cup volume)/(instrument volume) & (lead pipe length/(total length).
Although there may be more of these dimensionless ratios preserving the ones mentioned would keep the relative harmonic spectra the same for large scaled instruments as for the smaller ones.
One can hear how a properly scaled tuba would sound by recording a slow song played at four times the correct tempo on a flugel horn, using a real to real recorder running at 15 inches/second. One plays it back a 3.75 inces/second to hear it two octaves lower. Altough the attacks won't sound as good as on the flugelhorn, the tone is absolutely great.