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Discussion Starter #1
I would like a pair of subs in my '96 9c1 but don't want to take up much space. I already have a set of CDT 6x9's in the rear deck. Hack sells that backboard that sits behind the spare tire with 10' cut outs. This piece is a pressure fit. I have also seen the boxes that run along side the spare tire and output behind the rear seats. Which of these sound better and is sturdy?
 
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Discussion Starter #2
Im sure the boxes sound better.......then free air cutouts.

In case you didn't know, Thump is selling the boxes on here.
 
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Discussion Starter #4
Oh KEWL! We get to do this AGAIN! :D

Backboard!

(Waiting for ....... the others!)
 
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Originally posted by bbodyguy (o) (o):
Oh KEWL! We get to do this AGAIN! :D

Backboard!

(Waiting for ....... the others!)
What do you know about acoustics?
 
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Discussion Starter #6
Don't know Richard.
Just a dumb hillbilly with a " cheese dick instrument"! ;)

I know at concerts they have really big speakers....

[ 02-08-2007, 07:31 AM: Message edited by: bbodyguy (o) (o) ]
 
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Discussion Starter #7
Not being a car audio guy myself, I haven't a clue what "free air" means. However, literally, it means the lowest resonance the speaker produces while literally hanging by a "string" with no baffle board.

A baffle is needed to separate the front of the speaker cone from the rear. A speaker is a piston that moves air. However, without separating front from rear, frequencies from both combine, canceling and comb filtering - in other words, sound like crap. The baffle eliminates most of that problem.

If you can picture positive pressure from the front of the speaker, and negative pressure from the back, that is what the baffle separates. Perfect airtight seals aren't required for good bass response however. The worst problem in a car is rattling and/or whistling...

Then there is the matter of infinite baffle (sealed, airtight cabinet), which rolls off the lows very smoothly (depending on the size of the box), and ported (folded horn) cabinet design, which is (and should be) tuned to the speaker.

As a bassist, I prefer sealed. But you get better lows (or perceived lows anyway) from the ported design. I design and build my own bass cabinets using various CAD programs. The principles are the same. Ported can be tuned for the best kick, while sealed (or nearly sealed) will provide smoother lows, and stronger mids, and is easier, lighter weight and cheaper to build. I use tuned port ed cabinets on stage...

True "free-air" speakers would be very small and tin-y sounding. So, what does the slang "free-air" really mean? :confused:

[ 02-08-2007, 06:08 AM: Message edited by: Great SScott ]
 
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Free air and infinite baffle are the same in car audio jargon.
Hacks board is a free-air set up. I would not just use it as a pressure fit, however. You would need to screw it to the car, I used big screws from the passenger side and some open cell foam for it to compress against to get a solid mount.
It is really aproximating an infinite baffle alignment. The speakers sold for this alignment are labeled "free air" for the most part. Meaning the suspension of the speaker is designed for it.
 
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