Quoted from Spyderturbo007:
My currently subfloor plan is an underlayment of Delta FL followed by 7/16" OSB.
I'm not sure that I actually need a subfloor, but I'm planning on a mixture of engineered hardwood and carpet. The theater gets a thicker subfloor, so dealing with the transition between a 1" subfloor in the theater and no subfloor would probably be a pain.
The subfloor would provide a thermal break from the slab along with a "softer" feel to the floor. I'm also a little worried about moisture accumulating under the pad if it were to lay directly on the concrete. I don't have any humidity issues in the basement, but I still don't want to deal with mold.
My dad keeps telling me he doesn't think it's worth the money.
I put in a Delta FL system with a subfloor. You should also put landscaping fabric beneath the Delta as the plastic can click against the floor. (This is suggested in the install instructions). I put in a floating floor above that and it looks and feels great. Definitely helps create a thermal break in the floor as we live in Michigan and it can get really cold in the basement in the winter.
For my walls, I put up 3/4" foam panels and then walls with insulation in between the studs. Keeps it pretty nice down there.