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View Full Version : How do yo figure out.....



Trixter
03-17-2003, 10:10 PM
Whan building a ported box, what is the formula in finding out the box size and port size to get it tuned to a certain freq.?

evo2k3
03-17-2003, 10:17 PM
Originally posted by Trixter
Whan building a ported box, what is the formula in finding out the box size and port size to get it tuned to a certain freq.?

you set the box size.....and the port area, then use http://www.jlaudio.com/tutorials/ports/images/Fb.gif

to calculate the length of the port....if your math isn't all that great it might be better to share your specs with the board and we can help you out with the calculations.

bumpin_8605
03-17-2003, 10:17 PM
go tho this site its pretty easy to use

http://www.carstereo.com/help/Articles.cfm?id=31

Trixter
03-17-2003, 10:25 PM
Originally posted by evo2k3
you set the box size.....and the port area, then use http://www.jlaudio.com/tutorials/ports/images/Fb.gif

to calculate the length of the port....if your math isn't all that great it might be better to share your specs with the board and we can help you out with the calculations.

If this formula is to find the port length, then where does the freq. come in at?

bumpin_8605
03-17-2003, 10:28 PM
that website is a hell of a lot easier. trust me

Trixter
03-17-2003, 10:31 PM
I would like to actually know how to do it. I'm a paper and pencil kind of guy. besides, I may not always have internet access.

Natheo
03-17-2003, 11:39 PM
that site just told me to use a 7 inch wide, 9 FOOT LONG, round port in a 2.2 cubeic feet box, for a single 12" brahma. where oh where did i go wrong?

Trixter
03-18-2003, 11:39 AM
A perfect example of why knowing the formula can be sooooo helpful.

evo2k3
03-19-2003, 09:25 AM
i gave you the formula......Fb is tunning frequency......where the problem come in to play?

Trixter
03-19-2003, 11:20 AM
Ahhhh. I got it. Thanks a lot.

Trixter
03-20-2003, 12:30 PM
So what does Av, Lv, and Vb stand for and where do you find them?

evo2k3
03-20-2003, 11:14 PM
the equation came from jl's website...heres the link to the port tutorial...it should help you out....http://www.jlaudio.com/tutorials/ports/index.html