I have been using a Sumvision Cyclone Micro 4 media box to play movie files through my LG smart TV. It has an HDMI connection.

Lately I have noticed that certain files play with 'washy' audio, almost as if the sound is coming from underwater, if that makes sense. Some of the files are mp4 files, but mostly mkv. I haven't been able to identify any commonality to the codecs being used, although I'm no expert and may have missed something.

I'm at my wits end trying to figure out what the issue is so I can fix it. I'd appreciate any ideas you might have.

Thanks in advance.