I need more outputs for my immersive speaker system. I currently have a Steinberg UR816C which conveniently gives me 8 DAW Direct outs. I need at least 4 more outputs to run to a 7.1.4 speaker system. Can I buy and interface another UR-C box and easily buss to these additional outputs?
in general, it should work.
I am using Asio4All drivers, which allows mixing ofsound cards of different vendors. Am using here two 7.1 AVRs, which connect to the PC onboard graphics card via HDMI. No special graphics card. Just the standard Intel HD xyz. Each HDMI connection carries 8x channels. Within Nuendo-> Audio Connections and Asio4Call selected, you can assign each of those 2x 8x = 16x channels to a member of the 7.1.4 output bus.
In particular with your UR816 and a UR-C, I am not sure. It may work provided that both devices use the same (Steinberg) driver. With ASIO4All it should work. Don’t know, whether this causes you other issues like slightly higher latency or so.
IIRC, I see latency in the 20ms ball park when using the above mentioned configuration (2x HDMI).
Other caveat: With my Steinberg UR242, the ASIO4All driver does not expose all its inputs and outputs, whereas with the Steinberg drivers, all inputs and outputs are shown (… but the HDMI ports are not).
maybe you use the Adat in and out for additional 8 channels, no trouble with drivers.
for 500€ you will get an RME Adat to analog used on Ebay or any other platforms.