Grass Valley Maestro Master Control Installation v.2.4.0 - Manual (Page 171)

MAESTRO Installation and Service Manual 171
3rd Step: Audio Sets
Figure 89. Mono to Center Surround and Stereo Up Mix
Figure 90 shows the mono source mapped to the left front and right front
outputs equally.
Figure 90. Mono to Left and Right Front Surround and Stereo Up Mix
Figure 91 shows mapping to all three front speakers.