Ambio 4 was quadrophonic sound technology commercialised in the early 1970s that could reproduce the ambience or sound information of a room as well as play stereo. Ambiophony was an extension of stereo reproduction to enhance the sense of realism and it could be used with nearly all stereo programme materials.[1]
The technology was included in receivers, amplifiers and music centres from manufacturers including Philips,[2] Ferguson Electronics and Bang and Olufsen[3] alongside mono and stereo playback. The electronics behind Ambiophony was based on, or similar to, the Hafler circuit.
