View Full Version : calculating port and volume, HELP ME!!

07-12-2006, 09:48 PM
I'm using this (http://www.psp-inc.com/psp-inc.com/cgi-bin/port_length_calculator.cgi) calculator to get my port length. I'm wanting my subs to see a final volume of 4.5 cuft with a tuning of 31 hz. Its giving me 30.85 inches. Do I need to add the volume of the port to the 4.5 cuft to get the final volume of the box?

PS- my old thread was a dead thread, so i started a new one with a more exact question.

07-12-2006, 09:56 PM
what size and how many ports are you using?

and yes, so need to add the port displacement to 4.5 to figure out how big of a box you need to build.

07-12-2006, 09:58 PM
yea you need to add the disp. of the length of the port/s to the box.
(if the ports will be internal)
what i do is go back to the box calc. and try to add a few inches to the box.
to make up for the disp. on the ports, dont forget woofer disp.

im still learning so if im wrong correct me lolz:crazy:

07-12-2006, 10:27 PM
so, if I want my subs to see 4.5 cuft, i need to add the subs displacement and port displacement.

4.5 cuft. + .14 cuft. (subs displacement) + 1.01 (2 6" round ports @ 30.85") = 5.65 cuft.

And the only thing that is left is adding in the bracing displacement.

Is that right?