I have a number of Sonos products connected on a strong WiFi network around my house. One of my Sonos Ones recently started to suffer from a very loud crackling/static noise during music playback. It happens more on moderately bass heavy tracks but is irritatingly intermittent. I have tried moving the unit between rooms but it presents the same wherever it is located. 
 

I have seen a few threads where others experience similar faults but they mostly seem to have some sort of connection with a Playbar - mine does not - it is effectively a standalone speaker.

Can someone please help? Many thanks