Grass Valley Maestro Master Control v.2.4.0 - Manual (Page 82)

MAESTRO User Manual 78
3rd Step: Audio Sets
Audio Group Substitution
The Audio Input table can be used to pre-configure an audio group substi-
tution. In
Figure 34 three stereo audio groups are defined. The source may
have normal stereo for the main program and the Cantonese output, but
the Mandarin channel is not available. In this case, it is desirable to substi-
tute the original stereo audio for the Mandarin rather than leave it silent.
Figure 34. Audio Group Substitution
Down-mix / Up-mix Mapping
The audio input tables can also be used to down-mix or up-mix a program.
A down-mix is defined as creating a new signal from an audio group with
many channels to a group with fewer channels. An up-mix is creating a
new signal from an audio group with a few channels to a group with more
channels.
Figure 35 on page 79 shows a down-mix of stereo to mono as well as an
audio group substitution. The original stereo program is down-mixed to a
mono version and then sent out the Mandarin output. The values of -6 dB
are used so that the mono sum will be at unity gain.