L/R Stereo

L/R, Lo/Ro (Left only / Right only), and 2.0 stereo are all terms for two channel stereo program intended to be monitored through only two speakers (Left and Right) and, more specifically, to not be decoded as four channel Dolby® Stereo LCRS (Left, Center, Right, and Surround). There are two likely reasons for this designation: aesthetic choice or technical necessity.

Aesthetically, content providers sometimes simply prefer to present material as Lo/Ro, as is often the case with DVD special features or interviews. Technically, there are some tracks, often from vintage stereo films, that originated as discrete LCRS but will not decode properly as Dolby Stereo LCRS. The phase relationship of the source material, although originally compatible with vintage discrete channel delivery, will exhibit steering anomalies when matrixed through the Dolby system, causing the stereo image to bounce around in a very distracting manner. These tracks are best monitored as originally intended – as discrete LCRS – but if a two-channel version is required, Lo/Ro will provide a reasonable playback experience.