box building question?

I am designing a box i plan on building for 2 12inch JL subz. How do i find out the diameter and length of the of tubes i need for the ports? Is it better to use just a single port or does more than one sound better? and if i use more than one is there anything special i need to do?

r ur subs made for a ported box??

I just made a box and I got all the info for the specs from the booklet about the speaker that came with it. It should have everything in there or at least mine did..from port sizes and diameters to hole cutout and recommended cu.ft. of the box.

or...if you don't have any of that, write JL an email thru their contacts on the website and see if they will give you the specs on it.