Klarinet Archive - Posting 001610.txt from 1998/04

From: Mark Charette <charette@-----.com>
Subj: Re: [kl] Vibrating Instruments vs. Vibrating Air Columns
Date: Tue, 28 Apr 1998 10:44:56 -0400

DGross1226 wrote:
> Aren't the frequencies of the vibrating reed in conjunction with
> the length of the air column being transmitted/modulated/reinforced via the
> body of a sympathetically vibrating woodwind instrument?

Yes ... but direct measurements of the amplitude of the
body vibrations vs the amplitude of the air column's
vibrations leads one to believe that the contribution of the
body vibration is negligible compared to the vibration of the
air column.

For example, when I played electric bass, the sound of the
electric bass _without_ amplifier was audible for a short
distance from my bass, and the body _did_ vibrate. Slaps
and plucks were audible for a longer distance (more energy
transmitted). I played a solid body bass; the intent of
solid body guitars is _not_ to absorb any energy from the
strings.

However, turning my amp on overwhelmed any acoustic sounds,
even at very low levels. Did the acoustic sounds change my tone
at low levels? Were they discernible? To me, yes, since I was
holding the bass and my ear was only a foot and a half (max)
away from the body. Did the audience note anything? Nope -
they heard the amplified version, pretty much directly from
pickup to amp.

Now, if I had a thin-walled semi-acoustic bass instead of
a solid-body one, there would have been a very discernible
difference; indeed, when I played a hollow body electric guitar
I used to "wave" my hands over the f-hole to induce changes in
tone.
--
Mark Charette, Webmaster - http://www.sneezy.org/clarinet
Business: charette@-----.org
-------------------------------------------------------------
"There is only physics involved in playing a clarinet poorly.
There is no physics involved in playing a clarinet well.
That is performed by magic." - Fizzisist, on the Clarinet BB

---------------------------------------------------------------------
For additional commands, e-mail: klarinet-help@-----.org
For other problems, e-mail: klarinet-owner@-----.org