1. Check the connection cables of the Smart TV and the home theater speakers to make sure they are properly connected.
2. Check that all Audio settings on your Smart TV are configured correctly.
3. Make sure the audio output of your Smart TV is set to the desired audio output (HDMI, cord, etc).
4. If you are using an HDMI cable, check that it is of good quality and meets all sound standards.
5. Check if any software updates are available for your Smart TV.
6. Restart all devices and reconnect them.