From: John Woodgate
Subject: Re: Acoustic Feedback reduction
Date: Sun, 12 Jan 2003 10:32:38 +0000
Organization: JMWA Electronics Consultancy
Reply-To: John Woodgate
NNTP-Posting-Date: Sun, 12 Jan 2003 12:18:08 +0000 (UTC)
X-Newsreader: Turnpike (32) Version 4.01 <5Z8C9wtxbnpWyFnyfFzqmVF739>
I read in sci.electronics.design that Phil Allison
wrote (in ) about 'Acoustic
Feedback reduction', on Sun, 12 Jan 2003:
> Do you have a copy of WW May 1974 ?
> There is a letter ( Howl
>Supression) from M. Hartley Jones who described a 5 Hz frequency shifter in
>the July 1973 edition. I repeated the experiment he describes with a delay
>unit, shifter and headphones. Fascinating.
> In the letter he says: "I found the absence of beat in the majority
>of musical applications rather mystifying at first, but the answer was found
>to lie in the delay between direct and amplified sound".
Well, that a sort of answer, but not a very deep one. WHY does the delay
have that effect? It seems unlikely to me that MH-J's 'destroys
coherence' is the end of the matter. One for Brian Moore, perhaps.
I can't do any tests myself because the only delay unit I have is a 2
ohm resistor in a box, and I doubt that half a mho is enough delay.
On second thoughts, propagation delay is available to everyone, even me.
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
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