User`s guide

Speaker Output level
To change Duet’s speaker output level (i.e the listening level of connected speakers):
1) Push the Multi-function Controller Knob until the
speaker icon is lit on the Duet’s display
2) Turn the controller knob to the desired listening level.
Speaker
The controller knob operates in parallel with any
software output controls.
Adjusting Input & Output Levels - Apogee Duet Quick Start Guide
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