In the "StudioLiveSoftware_ReferenceManual-EN_V6_210220171.pdf" it says in section 5.2.2. Channel Settings: " 3. Input Source. This drop-down menu allows you to select the source for the current channel. The following options are available: StudioLive Series III: Analog, Network, USB, or SD Card". SD Card, USB and AVB do not have the same capacities (AVB is 55x55 streams, USB 2.0 is 38x38), but the way they work is identical. If you want to play tracks back to the mixer, you need to choose the right input source per channel on your mixer.

Hope this helps.