designing the best box/building

hello, i own these two 12 subs KFC-3011 and ive had them for about 2 years now in a prefab box and i finally decided after about two weeks of research that prefab boxes just arent as good as built boxes. ive been looking at like every possible box for these subs in my car and it seems that they dont do as good as the do in a sealed environment versus a ported/vented and with a little research and some luck ive found that they might do well in a fourth bandpass sealed box. so here comes my question, how would i go about designing a box to accommodate my subs with this type of enclosure. i have the WinISD program but its just so confusing to me i can do math but when it comes to all this audio stuff and boxes it just makes my head hurt..so anyone out there generous enough to help me out with designing my box i would greatly appreciate it. i have done a lot of research on these subs and i know a lot about them from 2 years of owning them, they just don't hit lows as much as i want but that's fine with me i just want to put them in a box were they preform at there greatest potential. So any suggestions other than "get new subs" would be helpful i need all the information i can get. i am shooting for my subs to be able to "quake" so when people get near they can feel the bass rather than, you just be able to hear it inside of the car.. here is the owners manual for the subs: https://inform3.kenwoodusa.com/manuals/kfc-w3011.pdf Thank you, Christian.

Build your box 32" Wide  18"Tall 15" Deep

make sure there is a divider in th middle

get some 3" diameter PVC for 2 ports. one in each chamber 7" inches long

so your saying build a ported box for my subs?