I have a question, is it possible to connect two interfaces at the same time? For example, the UR22mkII and the UR44C and have the outputs and inputs of the two interfaces at the same time in Cubase.
I am no expert in this but I believe this is possible with a Mac but not a PC. In macOS you have the possibility to create an ‘aggregate device’, that is to say you can join two (possibly more) audio interfaces to your computer. In this situation, using macOS, you can ask the computer to ‘see’ them as one interface. I have successfully done this with two Zoom handheld recorders to make a 16 track portable recording setup.
I think this ‘aggregate device’ idea is available as part of the macOS operating system, nothing to do with Cubase. I don’t believe there is an equivalent in Windows.
Under macOS (coreaudio), this is done with an Aggregated device.
Windows needs extra software for it. A common solution is ASIO4all.
Keep in mind that the synchronization between the interfaces takes time, and it adds latency.
Low latency is not possible with that kind of connection.