Posted by Mickster on January 10, 2001 at 16:01:53:
In Reply to: Building a bass amp. READ THIS ONE. posted by RICHY on January 10, 2001 at 07:21:32:
: : I've been thinking about trying to build my own bass amp from scratch, has anyone done this before or know of any web sites about it?
: : I know someone who has built Sub woofer boxes to go in people cars, so he should know a bit about constructing the actual box. Plus I do a bit of electronics at my college. I was wondering should I have a go, or just leave it to the pro's and pay them for it?
: : Ideas will be much appreciated,
: : RICHY.
: Sorry when i wrote the above i was thinking of a combo amp which I did not state. But now I'm thinking of a separate amp and a speeker cabinate. Cheers.
Hey Richie, what's up. I've built my own stereo speakers about 20 years ago,
and, to be honest, they came out pretty bad.I knew a little, which I thought
was enough, and, it wasn't.I didn't use damping material inside(very important)
I bought just any crossover, which was mismatched to the woofer/tweeters that
I'd picked(just because they looked good)and lastly, I made the width of the
enclosure panels too thin.The speakers boomed like crazy(from no damping mat'l)
they had no highs(from the mismatched crossover)and they vibrated from being
too light.So why now am I trying to give you advise on building cabinets?
Not to discourage you, just to make you realize that building speaker cabinets
for a stereo system or for an instrument isn't hard, but, you must know exactly
what you're doing as far as all the components go.Let's just talk about a bass
enclosure for now.First, you have to decide what speaker(s) combination you're
going to build: 1x12,1x15,2x10,4x10,2x10 + 1x15,etc.Then you really should buy
the actual speakers first because all 12s or 15s or whatever size you choose
don't all have the frequency response and efficiency, and so, must be all ported differently.Then, if you're going to add a tweeter,which is a relatively
new feature on bass amps, you have to buy the correct crossover, which is critical, because this is not the point where the woofer stops and the tweeter
takes over, but, the point at which they're both radiating 50% of the crossover
frequency, eg: A crossover of 1000hz means at 1000hz the woofer is producing
half of the output, and, the tweeter the other half.As the frequency goes higher
or lower, then the woofer or tweeter produce more or less depending upon the
frequency of the musical note being sent to the speakers(drivers).I learned all this after my disaster boxes sounded sounded so bad that I took them apart.If you really like to tinker, go ahead, just plan to build these things like a
military operation.I like to build stuff too, but, after I bought a pair of
Bose speakers that measure 31"x 7.25"x 7.25" that have 5.25" woofers, and
shake the house like nobody's business,I realized that Dr.Anmar Bose,who has
a P.H.D. in acoustics knows a little more than me.One book I can recommend is
Good Sound by Dr.Laura Dearborn.This book explains anything that anyone could
want to know about stereo/sound reinforcement sytems and amplifiers.
The bottom line is: If you're good at building stuff, and, you take your time,
you'll have the satisfaction of making something that you'll always use, and,
that everyone can see; If you just want to play, pay the man.
Hope this helped,
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