You can also select the audio channels of the input:
Audio bitrates will automatically increase when selecting 5.1.
If you select 5.1, we will send 5.1 to the Apple TV 4K and downmix for all
To downmix from 5.1 surround sound to stereo, we use the matrix
recommended in RFC 7845 (which defines Ogg encapsulation for the Opus
codec, and is also what the WebRTC ‘multiopus’ implementation is based
on). This matrix appears to yield better results than the LtRt or LoRo
matrices defined in the ATSC standard for digital audio compression,
mainly because it does not discard the LFE channel and has less impact on
the dynamic range of the audio signal.