Klarinet Archive - Posting 000468.txt from 2000/08

From: Tony@-----.uk (Tony Pay)
Subj: Re: [kl] Unloading.....
Date: Thu, 17 Aug 2000 08:54:52 -0400

On Thu, 17 Aug 2000 13:37:36 +0100 (BST),
roger.shilcock@-----.uk said:

> On Thu, 17 Aug 2000, Tony Pay wrote:

> > Do you mean perhaps that you have a difficulty seeing how Fourier's
> > theorem relates to reality, and want to know whether the overtones
> > are 'real', in some sense?

> Yes -- that's exactly what I mean.
>
> Roger

Well, the overtones in the harmonic case -- a clarinet, say -- are
audible; if you listen to your low F, you can hear the C a twelfth
above, and the A a sixth above that, and so on. So they're real in that
sense. And they're harmonic, ie in whole number ratios with each other.

You can hear the overtones on a piano, too. As I said, they get a bit
flat as they go up, because the normal modes of oscillation of the
strings aren't in exact whole number ratios.

What may help is to realise that the normal modes of oscillation of a
*clarinet* aren't in exact whole number ratios, either. But a piano
string *has to follow* its normal modes. A clarinet can't, because it's
oscillation is 'driven'. It settles into a mode of vibration, a whole
number template, that is a best compromise, in some sense, between the
normal modes (the natural resonances of the tube).

There's a post about that, too. See:

http://www.sneezy.org/Databases/Logs/1999/01/000043.txt

Hope that helps. Try to write two sentences next time.

Tony
--
_________ Tony Pay
|ony:-) 79 Southmoor Rd Tony@-----.uk
| |ay Oxford OX2 6RE GMN family artist: www.gmn.com
tel/fax 01865 553339

... My haystack had no needle!

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