A timely thread! I have a D-Box here to check out, and I have to admit that I am utterly lost and need help.
The physical connections were easy. It passes audio, and does sound great. If I set RME 1 & 2 analog as my default audio output, I get sound by enabling the "Sum" button. If I set SPIDF as default audio, I get audio when enabling "Daw".
Beyond that I'm lost.
Does anyone have screen caps they can share that show how you've created in the VST inputs/outputs windows, and how you are assigning within Cubase itself? As has been noted, in this capacity the manual is useless.