Hi, my theater will be about 13.5' wide by 20' deep. I plan on two rows of seating with a platform in the rear (stadium). The front seats will be about 11-12’ from the screen (106”) What, in your opinion, would be the optimum height and depth of the platform? I’m thinking 10” high by 65” deep. I’m not sure I need that much depth, but would be necessary if I want to be able to walk in front of the rear seats on the platform. Also, how should I insulate it? The platform will be framed using standard floor framing method (joists 16" OC w/ 3/4" plywood glued and screwed), should I fill my platform with standard fiberglass insulation? Sand? Foam? Any advice is appreciated.