View Full Version : questions for Jmac and the experts for xxx 12 box

09-30-2004, 09:06 PM
Help needed from the experts.

12" xxx down firing

02 f150 extended cab.
I will use the 40 portion of the rear 60/40 split bench seat.

Looking towards the back of the truck, using 3/4" mdf
external box dimensions are...

18" wide
17" deep

I can go as high as necessary to accomodate multiple boards for port.
The bottom will be braced squared with 2x2's (1-1/2 x 1-1/2 actual)

I'm looking to end up with between 2.5 - 3 cubes
tuned to about 29 to 30. (unless the experts here advise different).

Can anyone run these numbers and give me final dimensions??

09-30-2004, 11:43 PM
20 inches high and your diminsions would give you 2.738ft3...I'd punch it in to see if it would work but I can't find xxx specifications on winisd. sry

10-01-2004, 07:40 AM
I read in a thread here that driver displacement is .19 cu and the following is from re's web site.


Fs 27.0 Hz
Re 1.9 DVC
Qms 4.52
Qes 0.44
Qts 0.4
Sd om2 480
Vas 56.5
Xmax 32mm
BL 17.1
SPL 1W/1m 85.9
RMS 1600 W
Max 2500 W

I notice that your calculation does not include driver, bracing, and port displacement.

10-01-2004, 07:51 AM
i got 18x17x27 with a slot port that is 15.5x2 and 37"long tuned @30Hz
psthe box dimentions are external.

10-02-2004, 12:11 AM
TTT (10 chars)

10-03-2004, 01:26 PM

10-03-2004, 02:52 PM
what was wrong with the dimentions i gave you?

10-04-2004, 08:19 AM
Nothing "wrong" with what you gave, just wondering if anyone else has ideas/suggestions. Thanks for the info you have supplied.

10-12-2004, 03:36 PM
i got 18x17x27 with a slot port that is 15.5x2 and 37"long tuned @30Hz
psthe box dimentions are external.

Thanks jellyfish. I've kinda changed my mind though. Instead of down firing, I think I'll go up firing. Pretty much same dimensions, but do you think I could fire it up with the port on the same face as the sub, but use a 3 inch port and tuned to about 33-35? How long should the port be and should I go larger than 27?

Thanks for any help