Author Topic: The mor I read the more Im confused! Basement HT & MBD soundproofing plz hlp  (Read 2712 times)


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Hello I have been searching but seem to be getting More confused!
I have gutted my basement and plan a change to a master bed and theater. The theater is not dedicated, there will also be a bar and dance / Game area.

I am on a very tight budget so I am looking to cut some corners.
The wall between Home theater and MBR has an existing 2x4 wall with 3/8 drywall on 1 side and 3/4 Pine panels on other. I plan to add a 2nd wall infront of the pine wall. It seems to be that wood is a bad soundproofer so would I be better off to remove the wall and do a staggered metal frame with 2 layers of Drywall on HT side then 1 on MBR side? Or leave the wall and add dbl layer drywall on HT (pine side)?

I read that roll roofing is a less expensive solution to MLV? anyone care to agree or disagree?

Cotton vs. Fiberglass insulation again I read cotton but then read dollar for dollar not much difference and unless reading with DB meter you will not "hear" the gains?

I have enough Foam deadning squares to put inside the wall since these are for deadning sound in a room would I really gain much to adding this in the seperating wall (vs. fiber / cotton insulation)?

Greenglue VS silicon? Since green glue seems to provide a cussion between the drywall to stop vibration - How does using regular silicon caulk compare?

Would adding a fabric layer between drywall layer accomplich soundproofing any better than silicone or greenglue?

Thanks in advance

Mark Daveis

  • Guest
Use concrete blocks and cement as its one of the cheapest ways we do it here in the UK. Or use poured concrete both of which have lots of mass.
Wood products can be heavier than drywall and work just as well and even pine is good if thick and heavy and drywall is still resonant just like wood.
Doubling or tripling the mass of an existing wall will only make a slight difference which may be only 5 stc or so in the real world which is not really noticeable. For an increase of 10 stc you need to increase the mass say 5 times or more. If the wall is 20 kg/msq then you have to make it more than 120 20 kg/msq which means lots of wood or drywall which will be expensive. So I would just use concrete blocks or bricks which is much cheaper than say 6+ extra layers of drywall.
Steel is a very good sound proffer because it weighs so much and even more than stone or concrete.
Rolled roofing works but not as good as mlv which has been made in the lab to work against a range of frequency's and the roofing contains bitumen which is a health hazard so I would avoid using in the home.
Insulation only stops the sound bouncing around in a cavity and does not absorb LF noise.
Silicon caulk dries solid while the GG stays viscous and much more limp so works better but you will still need a lot of caulk to get a thick layer like GG so may not be cheaper. But still caulk or rubber sheets will definitely increase damping but you will need more than the amount of GG to get as much damping so it wont be cheaper. Nowadays they also mix liquid latex into concrete so it cracks less and damps better.
Fabric wont work because its not springy or viscous. Many layers of fabric would work but we are talking inches thick here which would give enough mass and some limpness but very very expensive. :)