box desing

Hi I'm building my first box. I was looking for help in design and what material to you use. It is one zv4 15 in a 99 Suburban. So i have plentry of room. Any help would be great.

Ok I have 4 hx2 15s with upgraded dual spiders flat wound coils. 1500rms a piece. I have them in a 12cft. Box tuned suppose to be tuned in high 30s the port is 6in wide and 29in long. And they dont sound very good on music. Idk is that too much port or somthing. Only running them on my...