Mass loaded vinyl (MLV) and acoustic foam are two different materials used for soundproofing, and they work in different ways to reduce sound transfer through walls.
- Mass Loaded Vinyl (MLV): MLV is a dense and flexible material that is effective at blocking sound transmission through walls. It consists of a layer of vinyl loaded with heavy particles, such as barium sulfate or calcium carbonate. The mass of the vinyl and the added particles helps to reduce sound energy transmission by reflecting and absorbing sound waves.
MLV is particularly effective at blocking low-frequency sounds, such as those produced by machinery, traffic, or music with heavy bass. The dense nature of MLV allows it to add mass to the wall structure, which helps to inhibit the vibrations caused by sound waves and reduces sound transmission.
- Acoustic Foam: Acoustic foam is a porous material that is primarily used for sound absorption rather than sound blocking. It is made up of open-cell foam with a convoluted or egg crate-like surface. When sound waves pass through the foam, they enter the open cells and get trapped within the foam's structure. The foam absorbs the sound energy and reduces sound reflections within a room, thus minimizing echoes and reverberations.
Acoustic foam is effective at absorbing mid to high-frequency sounds, such as voices, musical instruments, or high-pitched noises. However, it is not as effective at blocking sound transmission through walls because it lacks the mass and density necessary to prevent sound waves from passing through.
In comparison, MLV provides better soundproofing performance for reducing sound transfer through walls because of its higher mass and density. It can block a broader range of frequencies, including low-frequency sounds that can be challenging to attenuate with other materials like acoustic foam.
It's worth noting that for optimal soundproofing, a combination of different materials and techniques may be used. For example, a common approach is to use MLV as a barrier to block sound transmission through walls and combine it with acoustic foam or other sound-absorbing materials on the interior surfaces of a room to reduce sound reflections.