Polycom SoundStructure C16 Design Manual page 475

Advanced Applications
The updated matrix is shown in the following figure.
In this matrix, the submix "Amplifier" is used to route the remote audio of the
combined system to the "Amplifier 1" virtual channel and the "Mics" submix
is used to send the combined microphones to the remote video participants
and to the "Phone 1 Out" remote participants. By changing the content of these
submixes it is easy to change the Room 1 audio routing.
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