ok...so im building a mock up box for a SX 15 for practice and to make sure i do it right. my quesiton is that if i want to make the box to RE specs which is 3.5 cubic feet, how big would the pieces of MDF have to be to make it that big inside? also, what do you guys recomend, 1 inch or 3/4. if i used 1 inch would i still have to add another layer to the face where the sub is facing out? any information would be appreciated. thanks.
If it were me, I'd go 1" all around and 2x .75" for the baffle. Since its a slot ported box you won't need to add any more bracing. Big ported boxes demand solid construction.