I'm at the initial stages of creating a dedicated cinema room with a room that was converted from an internal garage about 7 years ago. Unfortunately no soundproofing was installed at the time, and after carrying out a sound test you could tell. I played the first 10 minutes or so of Mad Max Fury Road at -20dB on the Anthem (so -10db really) with a 5.2 setup, so without the in-ceiling Atmos speakers. As would be expected, the room immediately above is the worst, but I could hear dialogue quite clearly in the kid's bedrooms across the landing, along with the rest of the very loud soundtrack of course. Barely noticeable outside though, which is good considering there is a triple width double glazed window. I would like to be able to have the volume fairly high when the kids are in bed, so after hoping I wouldn't need to soundproof, I'm wondering whether I now should. My concern is whether it will make much of a difference, as I will not be able to do it properly. The room is already narrow because of the need to conceal utility pipes and the consumer unit etc, so is just over 2.5m at the widest part, but only 2.35mm at the narrowest part, which unfortunately is where the projector screen will be. At that width I'll just squeeze in a 92" screen, so can't go any narrower. I've had a look through the info on http://www.soundproofingcompany.com and I could possibly go with the clip and double PB with Green Glue solution, but it would be very tight on the side walls. Worst case I would only be able to install rockwool between the brick and PB, but leaving the joists touching both PB and brick. I could do the same between the ceiling and floor above. Has anybody gone through the same exercise and managed to significantly reduce volume levels outside of the room? Does the clip method make much of a difference compared to attaching PB directly to the joists? How thick should the rockwool be, 100mm or 75mm? Should there be a gap between the rockwool and the PB? What about sockets and switches and other objects that break into the PB? Presumably they impact on soundproofing performance? Two of the walls are external, whilst the other two are internal. Is it necessary to treat all walls, or just the internal ones (as well as the ceiling)? My understanding as well is that none of the above options would have much impact on LFE, so the house will still rumble anyway? I'll also look at replacing the internal hollow door with a soundproof one, but only if I attempt to soundproof the walls and ceiling.