When the processing demands of your session require a higher Buffer setting that causes disruptive latency, Direct monitoring lets performers hear themselves through a separate mixer running on hardware DSP and controlled on Symphony Desktop's Touch-Screen Display and in Symphony Desktop Control software.
The Direct mixer avoids the latency-inducing round trip through the DAW.
To avoid double monitoring, the DAW must be configured so incoming audio to be recorded is NOT monitored through the DAW.
To enable Direct Monitoring using the Symphony Desktop's Touch-Screen Display, press the output selector twice until "Assignment" box shows up.
When "Assignment" box is shown, press the box below, then choose "Mixer 1 or Mixer 2".
Then press Mixer View button to show signals and mixer settings.
You can press individual buttons (# 2-5 in the screenshot above) within Mixer View to change Channel Settings within Mixers.
For more information on Channel Settings within Mixer View, please refer to Pgs. 29-30 in Symphony Desktop User's Guide: https://apogeedigital.com/pdf/SymphonyDesktopUsersGuide.pdf
Another way to assign Mixer as the source to Output is in System Settings.
Here you can quickly change the Source to all of the outputs of Symphony Desktop.
Lastly, here are two videos showing you how to enable Mixers for output.
From Output page:
From Settings page: