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Path: utzoo!linus!philabs!cmcl2!seismo!harvard!talcott!panda!teddy!rdp
From: rdp@teddy.UUCP
Newsgroups: net.audio
Subject: Re: RAW SPEAKERS
Message-ID: <1042@teddy.UUCP>
Date: Mon, 29-Jul-85 12:56:29 EDT
Article-I.D.: teddy.1042
Posted: Mon Jul 29 12:56:29 1985
Date-Received: Wed, 31-Jul-85 23:27:13 EDT
References: <3177@decwrl.UUCP> <28400013@smu> <1036@teddy.UUCP>
Reply-To: rdp@teddy.UUCP (Richard D. Pierce)
Organization: GenRad, Inc., Concord, Mass.
Lines: 23

In article <1036@teddy.UUCP> rdp@teddy.UUCP (Richard D. Pierce) writes:
>
>First of all, for a given sound pressure level, the amount of excursion
>(displacement) is proportional to the inverse square of the radiating
>area, so that at a given frequency, an 8 inch woofer must have a total
>excursion TWICE that of a 12 inch woofer.

OOOPS, what I meant to say was the amount of excursion is proportional
to the inverse square of the DIAMETER of the driver, not the area. But
the example I give is correct, as I was computing the areas there. What
we are trying to do is maintain a given "volume velocity" for a given
sound pressure level so that:

	Volume Velocity = radiating area x velocity

and since the area is proportional to the square of the diameter, the
necessary velocity is reduced by the square of the diameter. For a 
given frequency, the total displacement is proportional to velocity,
etc., etc.,

Sorry...

Dick Pierce