Tuneable Helmholtz resonators ?

[Richard Moody]

----- Original Message -----
From: Bill Ballard <yardbird@pop.vermontel.net>
To: Sarah Fox <sarah@gendernet.org>; Pianotech <pianotech@ptg.org>
Sent: Monday, December 02, 2002 11:17 PM
Subject: Re: 90--110 DB (very OT)



> I thinks it's time to hook up two tweeters each to its own
frequency
> generator, with an oscilloscope in between. Pick two original
> frequencies well within the hearing range, say 10KHz and
10.44KHz.
> (Their spread represents a comfortably audible frequency.) See
if we > can hear a 440Hz tone. And if we can't hear it, can a
microphone
> plugged into an oscilloscope find it?
>
> Bill Ballard RPT
> NH Chapter, P.T.G.
>

Or use a Helmholtz resonator?   I day dream about how such a thing
could be hooked up to a stethoscope and tuned through a wide range
of frequencies, like filling it up with water or a piston making
it larger or smaller.      ---rm