the main floor of my theater should it be concrete or should i build a floor over existing slab with 2x4s and 3/4 ply - either way it will have carpet and padding. im just wondering if i want that vibration that is emitted from my subs that i currently get in my living room wood floor, i am going to install tactile transducers in the seating area anyway,but would this be too much vibes ? . the stage - should i even fill that with sand then??