Dolby Surround
From Wikipedia, the free encyclopedia
Dolby Surround was the earliest consumer version of Dolby's multichannel analog film sound format Dolby Stereo.
When a Dolby Surround soundtrack is produced, four channels of audio information—left, center, right, and mono surround—are matrix-encoded onto two audio tracks. The stereo information is then carried on stereo sources such as videotapes, laserdiscs and television broadcasts from which the surround information can be decoded by a processor to recreate the original four-channel surround sound. Without the decoder, the information still plays in standard stereo or monaural. The Dolby Surround decoding technology was updated during the 1980s and re-named Dolby Pro Logic. The terms Dolby Surround and LtRt are used to describe soundtracks that are matrix-encoded using this technique.
| Dolby Surround Matrix | Left | Right | Center | Surround |
|---|---|---|---|---|
| Left Total (Lt) | <math>1</math> | <math>0</math> | <math>\frac {\sqrt 2}{2}</math> | <math>j \frac {\sqrt 2}{2}</math> |
| Right Total (Rt) | <math>0</math> | <math>1</math> | <math>\frac {\sqrt 2}{2}</math> | <math>k \frac {\sqrt 2}{2}</math> |
j = + 90º phase-shift, k = - 90º phase-shiftde:Dolby Surround es:Dolby Surround hu:Dolby surround it:Dolby Surround
