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Path: utzoo!linus!philabs!cmcl2!seismo!hao!nbires!opus!rcd
From: rcd@opus.UUCP (Dick Dunn)
Newsgroups: net.audio
Subject: subwoofers (small-driver magic?)
Message-ID: <176@opus.UUCP>
Date: Wed, 30-Oct-85 01:40:59 EST
Article-I.D.: opus.176
Posted: Wed Oct 30 01:40:59 1985
Date-Received: Fri, 1-Nov-85 03:08:37 EST
References: <808@psivax.UUCP>
Distribution: na
Organization: NBI,Inc, Boulder CO
Lines: 32

> >Before everyone runs off and builds subwoofers with two 8" drivers,
> >I'd like to point out that this isn't going to be much of a subwoofer.
> 
> Ahem...the audio-pro B2-50 subwoofer uses (2) 5-1/4" drivers and I
> believe it is fairly flat down to 20Hz.
> 
> A friend of mine designed a subwoofer based on the audio-pro idea.  He used
> 2-6" phillips drivers in acoustically isolated, ported, cabinets...

Could someone explain what sort of magic is used to make this work?  I
assume that if these small subwoofers are not only flat down to the bottom
end of the spectrum but can actually produce reasonable sound levels down
there, there's some form of mechanical transformer effect due to enclosure
and/or placement.  Reason:  If you've got tiny little speakers like those
mentioned and they're just flapping around in the open air, you end up
having to move the cone an inch or two to slosh enough air around to make
any usable noise.  Even if you could get that much cone travel, you'd
manage to have some interesting distortion problems.  You can presumably
get around the problem by something with enclosure and/or driver placement
which presents enough load on the driver to reduce cone travel--trading
volume of air moved at the driver for pressure.

SO, could someone who knows explain how they work?

Oh, while I'm at it, could two or three people who know nothing about the
matter flame me after reading only half of my question, or agree with me
completely and flame the people who think small-driver subwoofers can work?
(No, I really don't WANT this--but you can sometimes get what you ask for
by asking for what you know you're going to get.:-):-)
-- 
Dick Dunn	{hao,ucbvax,allegra}!nbires!rcd		(303)444-5710 x3086
   ...At last it's the real thing...or close enough to pretend.