Room acoustics describes how sound behaves in an enclosed space.
The way that sound behaves in a room can be broken up into roughly four different frequency zones:
* The first zone is below the frequency that has a wavelength of twice the longest length of the room. In this zone sound behaves very much like changes in static air pressure.
* Above that zone, until the frequency is approximately 11,250(RT60/V)1/2, wavelengths are comparable to the dimensions of the room, and so room resonances dominate.
* The third region which extends approximately 2 octaves is a transition to the fourth zone.
* In the fourth zone, sounds behave like rays of light bouncing around the room.
Reverberation of the room
After determining the best dimensions of the room, using the modal density criteria, the next step is to find the correct reverberation time. The reverberation time depends on the use of the room. Times about 1.5 to 2 seconds are needed for opera theaters and concert halls. For broadcasting & recording studios and conference rooms, values under one second are frequently used. The recommended reverberation time is always a function of the volume of the room.