Re-occurrence of old issue. At the start of video playback with dolby/dts audio pass-through to receiver there is loud cracking from speakers.
There is old thread @popcornmix had a look.
OpenElec 6.0 DTS/Dolby causing speaker cracking
The issues was related to MMAL acceleration and the solution back then was to use alternative hardware acceleration.
I have tried switching off MMAL acceleration off and the issue now still occurs.
I played around with audio settings 'keep audio device alive' and 'send low volume noise' no luck there.
The only thing that stops it now is turning off audio passthrough.