Dell U2913WM Monitor - Manual (Page 27)

Attaching the Soundbar AX510 / AX510PA (Optional)
CAUTION: Do not use with any device other than the Dell Soundbar.
NOTE: The Soundbar power connector (+12 V DC output) is for the optional Dell Soundbar AX510/AX510PA only.
To attach the Soundbar:
1. Working from the back of the monitor, attach the Soundbar by aligning the two slots with the two tabs along the bottom of the monitor.
2. Slide the Soundbar to the left until it snaps into place.
3. Connect the Soundbar with the DC power connector.
4. Insert the mini stereo plug from the back of the Soundbar into the computer’s audio output jack.
For HDMI/DP, you can insert the mini stereo plug into the monitor’s audio output port.
If there is no sound, check your PC if the Audio output is configured to HDMI/DP output.