Mixing
Overview
Provides specific control over both left and right signal and balance levels. This simple operation can be used to downmix stereo material into mono, invert waveforms, transcode left/right stereo into mid/side, subtract a center channel, and much more.
Controls

Left Output Mix (%)
Allows you to define how much of the current selection’s left and right channel signal will be present in the new target left channel.
Right Output Mix (%)
Allows you to define how much of the current selection’s left and right signal will be present in the new target right channel.
RX 9.3.0