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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: <975@teddy.UUCP>
Date: Fri, 19-Jul-85 08:55:14 EDT
Article-I.D.: teddy.975
Posted: Fri Jul 19 08:55:14 1985
Date-Received: Sun, 21-Jul-85 00:20:57 EDT
References: <3177@decwrl.UUCP>
Reply-To: rdp@teddy.UUCP (Richard D. Pierce)
Organization: GenRad, Inc., Concord, Mass.
Lines: 40

In article <3177@decwrl.UUCP> mccamy@squirt.DEC writes:
>From: "...decvax!decwrl!rhea!Squirt!McCamy"
>Merrimack, New Hampshire
>
>
>I'm interested in building my own speakers and am not sure what speakers to 
>purchase.  I have heard a lot of good things about a company called 
>Speakerlab.  Has anyone had any experience with this company?  
>
>Any recommendations of other companies?
>
>I prefer a minimum woofer size of 12", horn type midrange and tweeter, and
>prefer an acoustic-suspension type system over the bass reflex.

I am afraid that the requirements you set out for the components are
quite incompatible!

First of all, there will be a wild mismatch in efficiency between the
bass and mid/treble units, possibly more than an order of magnitude!
This is not only going to cause problems with overall frequency response,
but the crossover is going to be a pain to do. The primary advantage to
horn units is efficiency, but your going to have to throw away every bit
of that advantage in the crossover to get the units to match out-put-wise.

Secondly, the overall response characteristics of horns tends to be much
poorer than that of good direct drive units, claims of manufacturers (JBL,
etc) and horn afficianados not withstanding. In experiments performed when
I was working for JBL and later as an independent consultant, it was
decided that it was impossible to physically realize a horn driver with
anything approaching the frequency/phase/dispersion linearities of suitable
direct drivers.

(Please don't flame me for this, as I am sure I have spent much longer
working on this and similar problems than the vast majority of people,
including most "speaker engineers", and I don't have the time to respond
to incensed replies. Reasonable queries is something different, though).

About SpekerLabs, I have little direct information. For direct drive units,
I am familiar with the Dalesford importer, and can recommend some of there
units highly, if they are still available.