I'm in the process of building a home theater in the basement, currently planning the ceiling. We've installed spaced wooden battens (CC 30) and are considering screwing up gypsum board. Since the ceiling height is so low, I can't build the ceiling too thick. The options we've considered are either a single layer of 15mm fire-resistant gypsum board or two layers of 6mm renovation gypsum. The question is, which is preferable for the best sound insulation? Or is there perhaps another better alternative?
15 mm best in terms of sound. Plus heavy insulation in joists.
I assume you want to shield the sound from the cinema against the surroundings? Then the question is, which frequency range is most important? A plasterboard on a sparse panel acts as a membrane absorber, effective against low sound frequencies. The longer the c/c distance between the sparse panels, the lower the resonance frequency. I would imagine that c/c 30 is best around 500-600 Hz. Then you can drill holes in the board at regular intervals and place mineral wool behind it to make it more broadband as an absorber. Why not start with a renovation plasterboard and experiment? The execution of the floor towards the next floor naturally affects the conditions as well. It's been quite a while since I dealt with this type of problem. There are others on the forum who are more knowledgeable.
Tool enthusiast
· Stockholm
· 1 399 posts
Fire-rated plasterboard insulates sound better than standard plasterboard. The more layers of plasterboard, the better, for the same reason Justus mentions. The problem with just one layer of plasterboard is the joints. With more layers, the joints are staggered, and you get a tight installation. The joints should also have a backing to ensure a good result.
As you probably know, the size of the air gap, insulation, and board material above are crucial for how good sound insulation you get. With a normal wooden beam structure and floor chipboard on the upper floor, you can't expect much isolation of the low frequencies. The construction will not isolate the subwoofer. Considering the low ceiling height, you could use 1 fire-rated plasterboard + 1 renovation plasterboard.
As you probably know, the size of the air gap, insulation, and board material above are crucial for how good sound insulation you get. With a normal wooden beam structure and floor chipboard on the upper floor, you can't expect much isolation of the low frequencies. The construction will not isolate the subwoofer. Considering the low ceiling height, you could use 1 fire-rated plasterboard + 1 renovation plasterboard.