Grass Valley Maestro Master Control Installation v.2.4.0 - Manual (Page 173)

MAESTRO Installation and Service Manual 173
3rd Step: Audio Sets
Figure 92. Stereo to Left and Right Front Surround Up Mix
However some customers report that their listeners prefer to always have
something in the center channel. Below in
Figure 93 , a center channel is
created by mixing the left and right signals together. The gain values are
adjusted lower in this case to present a consistent sound level.
Figure 93. Stereo to Left Front, Right Front and Center Surround Up Mix