Ambisonics - Advantages

Advantages

Ambisonics offers a number of advantages over other surround sound systems:

• It is isotropic in that sounds arriving from all directions are treated equally (as opposed to most other surround systems that assume that the main sources of sound are frontal and that rear channels are only for ambience or special effects).
• All speakers are generally used to localise a sound in any direction (as opposed to conventional pan-potted (pair-wise mixing) techniques which use only two adjacent speakers). This gives better localisation, particularly to the sides and rear.
• The stability and imaging of the reproduced soundfield vary less with listener position than with most other surround systems. The soundfield can even be appreciated by listeners outside the speaker array.
• A minimum of four channels of information are required for distribution and storage of a full-sphere soundfield, and three for a horizontal soundfield. (This is fewer than other surround systems). Full-sphere replay requires a minimum of six loudspeakers (a minimum of four for horizontal), the signal for each speaker position being derived using appropriate circuitry or software.
• The loudspeakers do not have to be positioned in a rigid setting; most regular polygons and (with somewhat more complex technology) a number of irregular figures can be accommodated. This allows the speaker configuration to be matched more closely to real listening environments, such as domestic living rooms.
• The Ambisonic signal is independent of the replay-system: the same signal can be decoded for varying numbers of loudspeakers (in general, the more speakers, the higher the accuracy of the reconstructed soundfield). This allows flexibility for composers, performers and production teams to produce a "final" mix without worrying about how the mix will later be released and decoded.