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Path: utzoo!linus!decvax!harpo!eagle!mhuxi!houxm!ihnp4!ihldt!dbg
From: dbg@ihldt.UUCP
Newsgroups: net.audio
Subject: re: building speakers
Message-ID: <2035@ihldt.UUCP>
Date: Sun, 9-Oct-83 17:00:53 EDT
Article-I.D.: ihldt.2035
Posted: Sun Oct  9 17:00:53 1983
Date-Received: Mon, 10-Oct-83 10:33:43 EDT
Organization: AT&T Bell Labs, Naperville, Il
Lines: 48


I recommend building from scratch.  I also recommend going with
an uncomplicated two way system, with a simple 6db/o crossover
(cap in series with HF driver, coil in series with LF driver).  If
you try to get real fancy with your design, you'll almost certainly
get burned.  I know that from experience.  I've designed speakers
following the popular equations, and I've designed speakers ignoring
all parameters and just going on trial and error and intuitive
feel.  I would recommend a mix that tends toward intuitive feel.

Select a LF driver and enclosure, based on Thiele's equations, that
suit your needs (power, efficiency, low end, cabinet size, etc)
Experiment heavily with port size and depth, be generous with
fiberglass wool inside the enclosure (fasten it loosly to the walls),
and seal the enclosure permanently at the rear.  Don't spend
too much on the drivers and always front-mount them.  Any access
needed to the inside of the enclosure can be done thru the driver
mounting holes.  The enclosure should be made of particle-board.
You can always add brazilian rosewood veneer when you're done if
they sound good enough.  Select a HF driver by whatever means you
can (price, brother-in-law's recommendation, trial and error, etc),
but be sure the efficiencies are compatable.  Don't use a horn
tweeter with an inefficient LF design.  (Don't use horns at all.
The good ones cost too much and the cheap ones sound cheap)

Finding reasonably good, inexpensive drivers is part of the trick.
There are plenty of driver manufacturers around that produce
reasonable drivers -- CTS, Eminence, Peerless to name a few of the
older, not so expensive companies.  Altec, E-V, JBL charge big
bucks for their drivers.   I used to buy what I considered a pretty
decent tweeter from CTS by the case ($60 for 12).  It was generally
referred to as the "phenolic ring" tweeter.  The quality went way
down during their strike of the mid seventies, but I believe they're
back in production out of CTS of Brownsville, Texas.  I can't offer
any real recommendations for driver selection as I've been out of the 
business for a while and no longer have any accounts with driver
manufacturers.  

Another option that seems to have merits is a subwoofer system.
A pair of 6" two way units and a common subwoofer would be an
interesting project to try to build from scratch.  If you want 
to experiment, you might consider getting the McGee Radio catalog
from 1901 McGee St, Kansas City, Mo.  Lately they've been carying
10" and 12" subwoofers with dual voice coils (no fancy circuits
to derive a common channel for the sub woofer).  

			happy building,
			ihldt!dbg