Volume up and down on TV adverts and films, loses clarity

Sonos does not alter the volume it receives from your TV, so if the broadcaster is sending advertisements at a higher volume than the content you’re trying to watch, there isn’t much Sonos can do about that. 

I’m  not sure what you mean by looses (sic) clarity. In general, a broadcast in stereo will lose the center channel signal, and the voice will be coming instead from the right and left channels on your Beam, which may seem as those you’re not getting the same clarity as a signal that is broadcast in a Dolby Digital. I’ve not seen any company that has effectively been able to extrapolate a good ‘center’ channel from a standard stereo signal.

In the cases that you feel there is not enough clarity, you might want to open the Sonos controller, go to settings, then system, and finally about my system. There will be a line in the Beam’s information that will say Audio in: and tell you what kind of signal the Beam is receiving at the moment you ran the report. If you’re using ARC to connect the Beam to your TV, you may want to double check whatever device is feeding the TV the signal, to make sure it is sending a Dolby Digital signal. Or, you may want to complain to the broadcaster, and ask them why that show is not in a Dolby Digital.