Can you explain the science of this to me, skipping exterior walls? The walls have r-13 now between studs. Right now I have a simple iPod dock and the sound is hear clear as day in my bedroom directly above theater room. The ceiling was drywalled from builder to pass inspection. The other two walls are one leading into the mechanical room with the hot water tank a d the furnace and electrical control panel, the other is adjacent to my home gym. I assume I should drywall everything, then add my channels and clips to the non exterior walls, and ceiling with 2 layers of dry wall and green glue.