I started my floor in my theater last week. I put down green treated 1x2 glued down. Then glued/nailed down plywood to them. I didn't insulate the airspaces since my floor has always been warm enough. But I never gave thought to the affect the airspaces would have acting like a drum or whatever you want to call it. No way do I want to rip up that floor given how much of a pain it was to glue down. Are the air spaces that big of a deal or should I drill some holes and use something like great stuff to try to get some kind of insulation in there?