Xiaomi Mi 4K Laser Projector 150” User Manual page 17

Bluetooth Speakers
The projector has four high-quality built-in speakers with a total output of about 30 W.
The speakers can also be used as a standalone Bluetooth stereo.
Tweeter Full Range Speakers Full Range Speakers Tweeter
To use speakers as the Bluetooth stereo, press the Home button, then select Settings > Remotes & Accessories > Bluetooth speaker
mode from the home screen. Enable the Bluetooth function on your phone. Search and locate the projector name in the Bluetooth list,
then pair the projector with your phone.
Note:
To connect and pair with other Bluetooth devices such as speakers and earphones, select Settings > Remotes & Accessories > Add
accessory. Make sure the device is in an awaiting connection mode with its Bluetooth function enabled.