Isolating Airborne Noise Through Walls
The light weight and natural resilience of walls allow them to respond well to added decoupling, damping, and vinyl. For the same reasons, including mass with any of these three upgrades is also more significant for soundproofing walls than it would be in ceilings or floors.
WHAT WILL WORK
In order of highest performing to lowest performing
Decoupling will always provide superior isolation over all other soundproofing methods or products. The most efficient ways to decouple your wall in terms of installation and square footage loss is with the GenieClip® RST or HushFrame Raft. With this option, we strongly recommend removing existing drywall and attaching the clip GenieClip® RST or Raft directly to the studs for maximum performance. An alternative to either is a double stud wall. However, to meet or exceed the performance of GenieClips® RST or Rafts, the double stud wall assembly will end up around 12” thick, about double the thickness of a GenieClip or Raft wall assembly. View the GenieClip® RST or HushFrame Raft.
Adding Green Glue Compound between two layers of drywall is a mass loaded vinyl alternative that will provide significant gains in mid to high frequency isolation, as well as moderate gains in low frequency isolation. View Green Glue Compound tubes or Green Glue Compound pails.
Depending on expectations, mass loaded vinyl alone may be enough for your project. This material will not help with isolation of low frequencies, but will help resolve typical resonance issues found in common construction materials. Contrary to popular belief, the mass of the vinyl is insignificant relative to the structure. How the vinyl resonates differently (essentially no resonance) than the other materials in the wall is what creates the value of the vinyl. View the TotalMass MLV.
Combining decoupling with damping will increase performance significantly. Mass loaded vinyl can also be used with Green Glue Compound if sandwiched between two layers of drywall. Sound tests of mass loaded vinyl in a resilient clip system show little to no gain over the standard resilient clip performance.
WHAT WILL NOT WORK
In no particular order
ADDING A LAYER OF DRYWALL
An additional layer of drywall will do little to isolate sound in a non-resilient wall. If the drywall layers quadruple, then some decent gains can be reached. This means a standard two drywall layer wall would need eight layers for significant gains.
Including sound board in a wall or ceiling is about as valuable as adding a layer of drywall.
LOW LEVEL PRE-DAMPED DRYWALL
Some pre-damped drywall performs well, but is hugely expensive and difficult to install. The versions found at leading hardware stores are cheaper and easier to install, but do not perform exceptionally well, roughly about as well as mass loaded vinyl.
Insulation is necessary in partitions to avoid resonance issues (basically a drum effect), but provides little isolation in a standard framed wall.
FOAM STRIPS, NOISEPROOFING TAPE, OR SIMILAR ON STUDS
These tapes, whether a foam material or rubber, will not help to isolate sound. The drywall screws or nails will penetrate the foam directly with the pressure of fastening compressing the foam as if it were not even there.