So I am trying to stream my setup to Mixlr, which provides a streaming interface where I can assign an audio device to send to the stream. There are a few options in the dropdown menu for each of the Scarlett 18i20's output channels, and there is one for the Scarlett 18i20's USB channel. Now I can hear both the audio from the Ableton Live DAW and the external instruments I have plugged into the audio interface, but I can't seem to get any audio from the USB channel, and the only time I do get audio from the interface to the Mixlr stream is if I select the 18i20's channels 3/4, which is the input channel used by the external instrument.
Has anyone successfully been able to get the USB audio source from a FocusRite audio interface to provide audio to the USB device? How do I get this to work? I need to feed to the stream both the external instrument and the audio tracks within the DAW.
I had a few problems with this, but it all comes down to how you use MixControl. Basically MixControl is like an intermediate patchbay between Ableton and your interface. Look under the loopback source, and see where that is being routed. My guess is that it is set to DAW (or input?) 3/4. Change that to an unused one, and use that is your input channel for Ableton.