Free encoding

An extension of spaced microphone recording techniques, systems which create pseudo-stereo from a mono source will also generate a strong surround signal, and stereo-width controls can be used to manage the balance between frontal and surround channels. Increasing stereo width also increases the level of the surround channel, whereas decreasing width reduces the surround content. This is because a surround decoder will automatically send anything which is of a similar level, but opposite polarity between left and right channels, straight to the surround output. Artificial reverberation, for example, is automatically spread across L, S, and R. See LCRS.