According to the manual:
Connecting a Balanced Audio Source
You can connect a balanced audio source to the AV controller’s BALANCE L/R INPUT jacks by using two XLR audio cables. To use the balanced input, you must assign it to an input selector (➔ 47). If you connect a mono source, use the BALANCE L INPUT jack and set the “Input Channel” setting to “Mono(L)” (➔ 47). The AV controller’s balanced INPUT jacks are wired as shown.
Pay attention to: To use the balanced input, you must assign it to an input selector (➔ 47).
Looks like you need to assign that input?
Connecting a Balanced Audio Source
You can connect a balanced audio source to the AV controller’s BALANCE L/R INPUT jacks by using two XLR audio cables. To use the balanced input, you must assign it to an input selector (➔ 47). If you connect a mono source, use the BALANCE L INPUT jack and set the “Input Channel” setting to “Mono(L)” (➔ 47). The AV controller’s balanced INPUT jacks are wired as shown.
Pay attention to: To use the balanced input, you must assign it to an input selector (➔ 47).
Looks like you need to assign that input?