Sony MVS-8000X User Manual page 714

Combination of Ch1, Ch2, Ch3, and Ch4
Mixing Ch1 and Ch2
If the Mix1 setting is 70, the proportion of the channels in the mixed portion in
the previous illustration is as shown in the following table.
Combination
Ch1 and Ch2
Mixing Ch1, Ch2, and Ch3
714
Global Effect Operations
Combiner
Indication in figure Ch1 Ch2
30% 70%