Tap the soundbar’s display, go to Speaker Setup > Levels > ‘Speaker Volume Control’ or ‘Bass Level Trim’, then swipe up or down to select the correct speakers and adjust the volume or bass level.  

Maintain a distance of about 10 centimetres between your subwoofer and any walls and avoid corners for the best bass experience.

This video shows an example how to adjust the Bass Level Trim (the Speaker Volume Control option is also available in the  Levels menu, when Citation Surround speakers are connected). Changes will be audible after saving.

NOTE: First update the WiSA module under the menu Options > Update.