DIAGNOSIS
Digital audio signal corruption. This is often caused by an incorrect audio format setting on the source device or a low-quality HDMI cable.
FIX
1. Change the audio output format on your source. On an Apple TV 4K, set Audio Format to 'Dolby Digital 5.1'. On a game console, set to 'Bitstream (Dolby)' instead of PCM for testing.
2. Replace the HDMI cable. Use only the supplied cable or a certified Premium High-Speed or Ultra High-Speed HDMI cable.
3. Disable any audio processing on the TV. Turn off 'Auto Volume' or 'Night Mode' on both the TV and within the SmartThings app for the soundbar.
IF THAT DIDN'T WORK
Test with an optical cable. Connect the TV to the soundbar via an optical cable (Toslink). If the popping stops, the issue is specific to the HDMI board or the TV's HDMI audio output.
HEADS UP
This popping is distinct from bass distortion. If the crackle is isolated to the rear speakers, it is likely wireless interference. Follow the rear speaker hiss/disconnect troubleshooting steps.