Downmixing is a general term used for manipulating audio where a number of distinct audio channels are mixed together to produce a lower number of channels.

Example

For example when converting 6 channel audio (for example 5.1 audio) to stereophonic sound (2 channels) the process is called downmixing. This example is a common feature of DVD players and Personal computer sound cards.

Stereo downmixes

Left total/Right total (Lt/Rt)

Lt/Rt is a downmix suitable for decoding with a Dolby Pro Logic surround sound device.

Left only/Right only (Lo/Ro)

Lo/Ro is a downmix suitable for stereophonic sound playback on a hi-fi or on headphones.