Fig. 1: Barrier, absorber, finish. Each layer does a different job and none substitutes for another.
The quick answer
Soundproofing a wall means adding mass, not adding absorption. The build is three layers in a fixed order: SoundBlanket MLV to block, BassBloc to stop the wall resonating, then a finish panel over both. It goes onto an existing wall with adhesive, no demolition, and it works because each layer does something the others cannot.
Walls transmit sound because they vibrate. A partition struck by sound energy moves fractionally and re-radiates that movement into the room beyond. Making the wall heavier makes it harder to move, which is the entire principle behind blocking airborne noise. Everything else in the build supports that one mechanism.
01 /Why walls are worth treating
- Sleep. Noise is one of the most common causes of disturbed sleep in urban housing, and a shared bedroom wall is usually the shortest path from a neighbour's living room to your pillow.
- Concentration. Research by Ipsos and the Steelcase Workspace Futures team, across more than 10,000 workers in 14 countries, found employees losing as much as 86 minutes a day to distraction.
- Privacy. Consultations, calls and confidential conversations need to stay in the room, which is a wall problem rather than a furnishing one.
- Property value. Acoustic performance is increasingly specified in premium residential and commercial fit-outs.
02 /The three layers
| Layer | Product | Job | Alone? |
|---|---|---|---|
| 1, barrier | SoundBlanket MLV | Blocks airborne sound by adding dense limp mass | The wall resonates |
| 2, absorber | BassBloc | Damps vibration and absorbs low frequency | Nothing is blocked |
| 3, finish | Acoustic panels, gypsum or HDHMR | Covers and protects the build-up | Decorative only |
The order is not interchangeable. MLV goes first because it is the barrier, BassBloc second because it damps the barrier behind the finish, and the finish last because the two technical layers are never left exposed.
03 /Installing on an existing wall
- Clean and dry the surface. Adhesive will not hold on a chalky or freshly painted wall.
- Fix the MLV. With SR Adhesive or nails, overlapping and sealing the seams. A gap in a barrier behaves like a hole in it.
- Fix BassBloc over it. Butted tightly, covering the full area rather than in patches.
- Seal the edges and penetrations. Sockets, switch boxes and the wall-to-ceiling junction. Back-to-back electrical boxes in a shared wall are a direct hole through it.
- Fit the finish layer. Felt panels, wooden slats, gypsum or HDHMR, covering everything beneath.
04 /Treat the wall the noise comes through
You rarely need all four walls. Identify which one the noise actually crosses and treat that. A studio is the exception, because sound leaving the room will find any untreated surface, but for a bedroom facing one noisy neighbour a single treated wall plus a sealed door delivers most of the benefit.
Related reading: soundproofing a bedroom wall from neighbours, and how effective MLV is.
05 /Frequently asked questions
What is the best material to soundproof a wall?
No single material does it. Blocking needs mass, which is SoundBlanket MLV at STC 30 or 34. Damping needs a dense absorber, which is BassBloc at NRC 0.90. Then a finish layer covers both. Any one of the three used alone will underperform, which is why the system matters more than the product.
Can I soundproof a wall without breaking it?
Yes. All three layers are surface applied to the existing wall with SR Adhesive or nails, then finished with panels or board. No civil work and no demolition. You lose a small amount of room depth, typically under 50mm depending on the finish you choose.
Will acoustic foam alone soundproof a wall?
No. Foam absorbs reflections inside your own room and has almost no mass, so it blocks very little of what crosses the wall. It is the right product for echo and the wrong one for a neighbour. Used as the finish layer over MLV and BassBloc it is entirely appropriate.
Do I need to treat all four walls?
Usually not. Treat the wall the noise actually crosses. A recording studio is the exception, because sound leaving the room finds any untreated surface, so studio isolation runs across all four walls and the ceiling.
Sonit writes about practical soundproofing for Indian homes and workplaces, with a focus on what delivers measurable results at sensible cost.
