i have 2 JL 12w3v2 in a random sealed box that wasn't built to specs. now i want to build a ported box for them. but im not sure on what dimensions i should use. i believe that the subs need 1.25 cubic feet each and i dont know how to figure out the dimensions i need. if anyone can help me design a box with the correct spec please help. the biggest box i can fit is 14in high (top/bottom) 37in long (left/right) and 15.5in wide (front/back)

 

here ya go:
http://www.the12volt.com/caraudio/boxcalcs.asp

 

a ported box is going to be bigger than a sealed box. they should have all the specs on jl's website.

 

i think you should build me a box!! haha..

 

Trinben is correct there is a lot more to ported then just building it. you have to know what freq. the box will be tuned to, and how long the ports will be. which what the box larger then a sealed enclosure. also look in to do a vented instead of a ported enclosure. see what the web site say.