Posted by Tubaman with a Plan on June 13, 2001 at 11:14:02:
In Reply to: Heavy Rotary Valve Caps posted by Tubaman with a Plan on June 12, 2001 at 17:07:12:
Someone down the thread line asked in the science behind this concept.
I'm not a scientist. But, after playing for over 20 years the main goal that I have concluded on is that "fullness of sound, superior tone quality, and projection" is what every tubist should strive for in their playing.
I have seen many external devices such as a belt around the bell, lead tape in the bell, mouthpieces with sound reinforcement walls. Material added external to the bows and slides.
Many areas have been isolated except the rotary casings themselves. It seems to me that the area most "prone" to an increase in harmonics and unnecessary vibrations would be the rotary mechanism.
The air starts from the mouthpiece and travels through the leadpipe. Air Friction increases and when it hits the rotary casings along with all of the moving parts, there are many different actions taking place. Don't know all of the terms, I am not a scientists. I would say there are alot of extra "vibrational" reactions that occur that cause the extra harmonics.
In my line of thinking, if the extra vibrations that contribute the unwanted harmonics could be eliminated or seriously curtailed, the harmonics that are added after the most "suspect" area of the instrument would be significantly lowered.
The "PURE" "true" sound that we invision coming out of the bell of the instrument would be greatly enhanced.
This is just my "theory". You do need to take into consideration the materials used in making the tuba, design, and other external factors. Example, does a bare brass instrument have different vibrational loss than an instrument that is laquered?
Just my professional insights.