In order to successfully use a 2.2 speaker configuration using the Dirac Processor plugin from within your DAW, you need to use a "Quadraphonic" output, and insert the Dirac Processor plugin on the Master Out (or "Control Room" output depending on which DAW is in use) channel.
Step 1. Go to the "Custom Channels Config" options through the Dirac Live Processor's main menu, select "Stereo" and click the "Add subwoofer" button two times. Then route the output channels as needed for your specific configuration.
Step 2. Close the "Custom Channels Config" window, and make sure to select "Custom" in the drop-down menu located in the top right corner of the Dirac Live Processor user interface.
Step 3. Put the Dirac Live Processor on your Master Out channel within the DAW, make sure it is set to "Quadraphonic", and you should now have sound.