box help

[MACnonsence6]

ok im planning to order another pair of hifonics 12s for my room. now for the box i want my other towers to be able to sit on top of them.so my question is can i build a box to 2.5 cubes with these dementions h-doesnt matter just as long as the sub is facing farward. w-31" and 20" deep idk the displacement of my sub yet im not to sure how to figure that out. but the port for the box would be 3" x 4.6 deep these are the specs from the site for 34hz my main question is well one how do i figure out the displacement of my sub so i can add that to the totall gross of the box. second using w,e material thickness could a box be built to those specs with those dementions

[SlamDUNKmyJUNK]

The specs on Hifonics's website should tell you the displacement, and I don't understand what you mean with the thickness. You can use what ever thickness you want, 3/4 of an inch would be fine.

[MACnonsence6]

well becouse of the dementions of the box i need compared to the internal cubes i need. thicker wood could give me the dementions i need while keeping the interal 2.5 thats if the dementions i need are to large to make 2.5 if that is the case that the box would be way to big to give an internal of 2.5 then i could also double the sheets of wood to make the outside what i need as well making the inside the size i need if that makes sence?

[MACnonsence6]

vas-107.4 liter sorry if thats wrong if it is let me know