sub displacment

hey everyone. i recently made a dual ported box for my alpine type x 12's and their not hitting how they are suppost to, im thinking i didnt make the box big enough, i created it on winISD but i forgot to account for the sub displacment, how do you measure something like that? any info would really help me out, thanks guys

The displacement of the subwoofer is not going to make an acoustically discernable difference.

WinISD does a great job with the response curve, but the 'voice' or 'tonality' of the woofer isn't really represented here -

What size box you make?  Did you port it?  What frequency is it ported at?

the box is 32w x 17d x 14h i made the port 21 in long and 12"x1" wide at 29 hz. winISD didnt have my driver on there so i entered the paramaters myself. this is my first time i built a ported box or even used winISD. i read the guide on here how to use it and it helped a lot but its still my first time messing with it i didnt double check my t/s parameters but im sure i wasnt to far off, if someone can help me out finding the right dimensions, port length, tuning hz  etc.. for these subs it would mean a heck of a lot,  thanks guys, ill post pics up once i rebuild it.

You said you made "a dual ported box" for "subs", so I guess you have 2 subs?

Then you described one port.  What exactly do you have and how did you design / build the box?

i made the ports the same? it looks something like this. nothing to crazy just a dual ported box, im tired of that pre fab "one size fits all" boxes so i came up with something basic, i used the same dimensions and ran it through winisd it  looked good to me, its loud,  i just want it to be able to shake the earth, you know those deep bone shaking notes. where do i go from here?