The following is the text of an article that appeared in the Two:1994
issue of Speaker Builder Magazine.  Enough folks have asked for this
prior to publication that I pre-printed it once to issue #400 of The
Bottom Line bass mailing list (for subscription information send e-mail
with the line "info bass-digest" help in the body to:  Please do not reprint it without my permission.
All rights to this article and the design described therein are

If you'll send me a self-addressed double-stamped envelope (or four
International Reply Coupons if you're overseas plus an envelope), I'll
be glad to send you a copy of the article, including the figures and

My current address:

	Len Moskowitz
        Core Sound LLC
	405 Cedar Lane, #1
	Teaneck, NJ 07666 USA

You can subscribe to Speaker Builder by contacting:

	Audio Amateur Publications
	Speaker Builder Magazine
	P.O. Box 576
	Peterborough, NH 03458  

As of April 2004, the drivers and crossover described in this article
are still available from Madisound Speaker Components

On February 24, 2005 we added a section at the end of this article about
parts availability.

                   A Compact Bass Guitar Speaker Bottom
		  ((c) Copyright 1993, All Rights Reserved)
                            Leonard Moskowitz
                            405 Cedar Lane, #1
                          Teaneck, NJ 07666 USA

I've been playing bass guitar since I was 11 years old.  That makes it
more than 25 years that I've been thumping away, holding down the bottom
end of the rhythm section.  Looking back I see that the world has
changed a lot during that period, but one thing has remained constant:
bass guitar speaker bottoms are still huge, still weigh a ton, and are
still a pain in the rear to haul around!

This realization struck me as good motivation to design a speaker bottom
that was small and light weight.  But that wasn't all I wanted!

Most bass guitars have four strings, with the lowest being E1 at 41.2
Hertz.  Two recent developments are the five and six string basses, both
having a low B string ringing out at 30.9 Hertz.  My new bottom had to
reproduce that low B cleanly.

In the old days, the star bass players like Carol Kaye and James
Jamerson used dull sounding flatwound strings.  They played through amps
like the Ampeg B-15 Portaflex that had one fifteen inch speaker in a
too-small sealed box, giving a pronounced peak in the mid-bass.  This
made bass guitars sound boomy and thumpy, and they lacked any
significant frequency content above roughly 1 kiloHertz.  Since the
seventies though, innovative bass players including Larry Graham, Sting,
Geddy Lee, and Jaco Pastorius popularized techniques like slapping and
popping, and sometimes using picks to increase definition and clarity.
These pioneers favored roundwound strings that rang out brilliantly like
a Steinway piano's low registers. My new speaker bottom had to reproduce
that high end too.

Since I had to compete with guitar players playing stacks of Marshalls,
this new bottom had to be reasonably efficient and loud.  And finally,
it had to be able to handle the roughly 200 Watts of power that a
standard bass amplifier like the Gallien-Krueger 400RB puts out.  Oh,
almost forgot: it couldn't cost an arm and a leg -- just an arm.

"Well," I thought, "that should be a challenge!"  And as you'll see, it


Couldn't I buy a commercially made bottom that did what I wanted?
Unfortunately, the answer was "no."

Perhaps the hottest ticket in small bass bottoms these days is SWR's
Goliath Ju