Posted by Eric on December 19, 2003 at 14:22:05:
In Reply to: Re: Engineered tuba revisited posted by Will on December 19, 2003 at 10:17:50:
I remember reading years ago about seperate studies done by both Conn and Schilke regarding bell materials for trumpets. The materials tried were brass, bronze, steel, lead, wood, fiberglass, concrete etc. There were two interesting conclusions as I recall. One from the Schilke test was that a lead bell produced a sound of such metallic brilliance that it was unuseable. The interesting result of the Conn experiment was that a concrete bell was judged by a blind panel to have the best overall sound.
It would seem from the schilke test and my own observations regarding the difference in sound between otherwise similar instruments made of fiberglass, brass, and nickel silver that that material from which instruments are constructed affects mostly the extreme high frequencies produced. A very heavy material with a very low stiffness such as lead tends to contain and reflect high frequency soundand absorb low frequencies whereas a light material with high stiffness and damping such as fiberglass tends to absorb the high frequencies and contain the low frequencies to such a degreee that it is diffult to hear yourself play. That is why I would really like to try fiber reinforced concrete such as used on concrete canoes. It has mass to contain the highs, stiffness to contain the lows, and low damping for less energy loss. Frankly, I dont like the metallic brassiness of a tuba being overblown. In fact, I have heard some fiberglass sousaphones that had quite a pleasant sound even when pushed to the extreme of volume.
Repairability is an issue, however just by looking at the progression of tools over the years for the repair of brass instruments it is clear that they are not exactly ideal in this regard either. One drawback of the two piece molded body is that you can't take it apart and add the bits and pieces to your tuba building block set like with traditional horns.