I am currently in the planning stages for a HT in my basement. The room is 17' 6" w by 20' 1" long with a concrete floor. I have talked with a local HT shop and they are recommending a subfloor and resilient channel for wall construction. I have seen Dennis Erskine and several others recommend no subfloor and 2 layers of dry wall (1/2" & 5/8"). That was the direction I was leaning in until they made it out to sound wrong. Can someone help clear my mind.