This page focusses on decoding of classic first-order Ambisonics. Other relevant information is available on the Ambisonic reproduction systems page.

The Ambisonic B-format WXYZ signals define what the listener should hear. How these signals are presented to the listener by the speakers for best results, depends on the number of speakers and their location. Ambisonics treats directions where no speakers are placed with as much importance as speaker positions. It is undesirable for the listener to be conscious that the sound is coming from a discrete number of speakers. Some simple decoding equations are known to give good results for common speaker arrangements.

But Ambisonic Speaker Decoders can use much more information about the position of speakers, including their exact position and distance from the listener. Because human beings use different mechanisms to locate sound, Classic Ambisonic Decoders it is desirable to modify the speaker feeds at each frequency to present the best information using Shelf Filters.

Some views on the complexities of Shelf Filters and Distance Compensation are explained in "Ambisonic Surround Decoders" and "SHELF FILTERS for Ambisonic Decoders".

There are specialised decoders for large audiences in large spaces.

Hardware decoders have been commercially available since the late 1970s; currently, Ambisonics is standard in surround products offered by Meridian Audio, Ltd. Ad hoc software decoders are also available.

There are five main types of decoder: