Posted by Rick Denney on June 14, 2002 at 12:33:43:
In Reply to: Re: Vintage vs. modern / thin vs. thick posted by js on June 14, 2002 at 10:33:56:
Furthermore, some old instruments stated to be thicker have been buffed to the point where they are now thinner, but still retain their essential playing characteristics. Joe has mentioned, based on close observation, that the famous Chicago York has been heavily buffed in its various overhauls, with no apparent ill effects on its playing qualities.
My own observation suggests that the physical resonance of the brass has a smallish effect on the resonance of the air it contains, and I can't really draw any connection between how much a tuba vibrates in my hands with how it sounds out front. Some apply damping devices to tubas, which can adjust high harmonics and sibilance to some extent, but I wonder what effect that has out in a live hall. I helped my wife's uncle choose an old King 2341 a few months back. That instrument rang like a bell at about 100 Hz, and I could induce the vibration either by playing the notes that would resonate it or by whacking the upper bow with the flat of my hand. Yet nobody could tell the difference in sound between those notes and others that didn't induce that vibration.
Based on these observations, I'm inclined to think that brass thickness and the resulting resonance has a small effect, and to agree with Joe that this effect is likely overwhelmed by other effects more related to the shape of the instrument, especially when evaluated out front. For a given instrument, adding mass or stiffness might change the resonance in useful ways (or in harmful ways), but generalizing seems difficult.
Rick "whose Conn 20J bell rings and rings, but who can't hear it ring more than five feet away" Denney