There are many kinds of sound studio foam used to improve the acoustics of a recording or music room. The most basic kinds of foam for acoustic enhancement, the ones that many people are familiar with, are sound proofing and sound absorbing foam. These two are often referenced together and used interchangeably, which is wrong because sound proofing foam is different from sound absorbing foam.
Sound proofing is for keeping sound contained within a room; or at least stopping sound waves from passing through the walls, ceiling or floors. The waves bounce off this foam, making the sound louder and more pronounced. On the other hand, rebounding sound waves also result in echoes and deep reverberations. These are not acceptable in a sound studio, particularly when a recording is going on.
That is why sound absorbing is also used to complement studio sound foam. This one allows sound waves to pass right through it and lets a certain volume of sound to be heard from outside the room. It works efficiently for sound reduction too. Most importantly, sound absorbing foam reduces the audibility of echoes and reverberations.
When used together, these two kinds of sound studio foam can improve the quality of the acoustics in the studio and will balance the need for sound isolation and reduction of unnecessary echoes.
Other Functions of Sound Studio Foam
Besides these two, there are also other kinds of sound studio foam that are used for other purposes in the sound studio.
For instance, there’s a special kind of foam that attenuates sound waves. This is the process of transporting sound waves from one room to the next. This is done by installing two separate layers of acoustic paneling on the ceiling with a gap in between. Sound waves coming from one room will pass through the ceiling and made to bounce on the second layer of acoustic paneling, and right through the ceiling of the adjacent room.
Sound attenuation may also be achieved by using sound absorbing foam on the inner ceiling and sound proofing on the upper ceiling.
Shapes and Specific Purposes
Sophisticated and high-end sound studios use sound studio foam that are made specifically for a particular part of the room and for a specific purpose. Two examples are bass wedges and soft-sound baffles.
There are also specially designed foams that fit into the corners of a sound studio. These are called corner trap foam. These are useful for ensuring that the volume of sound is even all over the room.
Imagine sound waves flowing through a closed, quadrilateral room. If the source of the sound is standing at the center (ex: the singer or musical instrument player), the sound waves will be hitting the various parts of the room at different angles. This means some sound waves will bounce back to the source earlier, some will come later—and those that will bounce back later usually come from the distant corners.
By installing corner traps, sound waves will be have a more uniform speed and rate of bounce—and this can be determined through the volume and formation of echoes in a room.