not related to rocco's

[vince@performancecarstereo.com (Vince Royer)]

Sounds like a really bad idea.  1st of all, you shouldn't combine 10" subs
with 12" subs, or any subs with any other.  The only time you have different
size speakers playing together is if you're sending them entirely different
signals.  You send higher frequencies to smaller speakers, and lower
frequencies to the big speakers.  If you're going to split the system up,
first decide how many ways you're going to go.  a 2 way system is like a
woofer & tweeter,  Or a pair of Woofers and Tweeters (matching pair).  a 3
way system would be a Subwoofer, a midrange/midbass driver, and a tweeter.
A 4 way system would be a Subwoofer, a midbass driver, a midrange driver,
and a tweeter.  It goes on and on, but any more than 4 ways is totally
overkill and will cause more sound problems than it will solve.  Always set
up the system as simply as possible for the application. If there are
problems (like low midbass response) then you can address those problems.
Don't just make things complicated for the sake of it.

Note Above when I say 'Subwoofer', that can be anything from a single 12"
sub to 20 10" subs to a Bose Triple bandpass 4" sub.  The important thing is
that they will all recieve the same group of frequencies (below 80-100 Hz).
So the problem with your 10"s and 12"s is that they are both subwoofers, and
both designed to play these 'sub-bass' frequencies.  By combining them and
playing the same frequencies through them,  you will create cancellation.
Think about waves in the ocean for a minute.  If 2 peaks from 2 waves crash
into each other, they will make a huge wave of their combined height, right?
If 2 dips from 2 waves crash into each other, it'll create a really big dip.
What if a peak collides with a dip? Then what?  Calm water.  No wave.
Silence.  Get it?  When the bass hits, your 10" subs will recreate a certain
wave, somewhat like the one that was recorded onto the cd.  Your 12" sub
will also create a certain wave like the one on the CD, but not EXACTLY. It
will be different than the one that's coming out of the 10" subs.  So the
waves will collide in weird places in the car and create flat spots, places
where there is no bass.  This will happen pretty much randomly and will be
worse in some cases then others.  The point is:  Pick your subs.  10" or 12"
1, 2, or 20.  It doesn't matter.  Just make them all the same.

The second thing about your idea is the fiberglass and bondo stuff.  Don't
mess with it unless someone shows you how.  It's just not worth the trouble.
You'll end up with a gross product that probably won't work or look very
good. If you really want to get your hands into it, just build a box for
your 2 10" subs.  You can't go too wrong that way.


-----Original Message-----
From: scirocco-l-admin@scirocco.org [mailto:scirocco-l-admin@scirocco.org]On
Behalf Of Rhett Farnum
Sent: Monday, November 18, 2002 11:36 AM
To: scirocco-l@scirocco.org
Subject: not related to rocco's



I am planning on adding sub tubs to my 92 cutlass on the panel behind the
back seat in the support bracing there. Planning on 2-10" and a single 12"
since there are 3 openings there. I am going to make the tubs myself since
they need to be custom.
Me really ? is any suggetions on what to use for molding or glassing
technique? Also and connections for places I can get gel-coat? I am planning
on using expanding foam and bondo for the mold.

Peace,
Rocco_crossing



Add photos to your messages with MSN 8. Get 2 months FREE*.
_______________________________________________ Scirocco-l mailing list
Scirocco-l@scirocco.org http://neubayern.net/mailman/listinfo/scirocco-l