From: rgonzal@gandalf.rutgers.edu (Ralph Gonzalez)
Newsgroups: rec.music.makers.bass,alt.guitar.bass
Subject: DIY bass cabinet notes
Date: 15 Dec 92 17:12:47 GMT
Followup-To: rec.music.makers.bass
Organization: Rutgers Univ., New Brunswick, N.J.


In case anyone's interested, here's a rely I sent to someone who was
asking about building his own bass cabinet. He was especially
interested in getting a clear midrange response.

-Ralph

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Speaker Builder is PO Box 494, Peterborough, NH 03458. Phone:
603-924-9464. I've seen one project for a big bass cabinet (I
think it's in the the 1990 backissues) which was pretty
ambitious, but most of the articles are for hi-fi systems.

For bass guitar it's nice to have the speaker flat down to
80 Hz or preferably 40 Hz. You won't find any full-range driver
which is really good for that. When you say you want the cabinet
to emphasize the highs, I assume you're talking about the mids
(200 Hz-1000 Hz), since no bass guitar I know of puts out any
signal in the range where a tweeter is active (above 2-3 kHz).
Try it -- if you put your hand over the tweeter while playing
your bass, the only difference is you hear less hiss from the amp.

What I've done is to use a single largish (only 12" - should be
15" I guess) woofer and a horn midrange to take over up to about
2-3 kHz.

If you only need to go up to about 2-3 kHz, you probably can do it
with a single driver or an array of the same driver. I've seen a
10" SEAS (25F-EWX) driver which has a very nice response up to
2 kHz and a gentle rolloff above this. I think this would fit the
bill for you. It has decent power handling and has a gradually
rising response which emphasizes the midrange. If you put it in
a properly-vented cabinet you can get bass down to 50 Hz. I would
suggest an array of 2 or 4 to get more power handling.

Or you can look into an array or 6.5" or 8" drivers, but you'll need
more of them and will end up paying more money.

You can get hi-fi drivers (and possibly some musical-instrument
drivers which presumably are a little more rugged) from A&S Speakers,
415-641-4573, and they should also be able to suggest how large to
make the cabinet, etc. (You have to multiply the cabinet size by the
number of drivers you put in it, though. Also multiply the number
of vents if it's a vented cabinet.) I think the aforementioned SEAS
driver is about $40 each.

Another good source is Madisound Speaker Components, 608-831-3433.
They
distribute several different brands (I don't think they carry SEAS)
and also sell their own line of drivers which go up to 15" at very
good prices (around $60-$70 for the 15" ones, I think).

Leave room on the front of the cabinet to insert a couple of midranges
later if you think it's necessary.

Anyway, by using 10" or smaller drivers you'll get a lot more
midrange than using a conventional 15" cabinet...

I don't know about not using paper cones for bass... there are a lot
of myths out there so this might just be one of them. For a while
there was a well-founded aversion to woofers with foam surrounds,
since these used to deteriorate after a few years. Modern foam
surrounds don't have this problem, though.
*************************************************************
-- 
Ralph Gonzalez, Computer Science, Rutgers Univ., Camden, NJ
Phone: (609) 757-6122; Internet: rgonzal@elbereth.rutgers.edu
--
Newsgroups: rec.music.makers.bass,rec.music.makers