There's already a thread about Era 300 sound clicks with some references to the 100, but we need one for the 100s.
My setup is two Era 100s as a stereo pair with a Sub, Trueplayed and playing FLAC files off local network NAS.
When I first heard the clicks my brain tended to disbelieve them as not possible - I've never had clicks on any Sonos device (had Sonos gear since 2007) and never expected to.
At first I thought my music tracks may have got corrupted so I played the track that clicked on another (non-Sonos) device - no clicks.
I found the Era 300 clicks thread and was dismayed to realise I’d bought a pair of defective speakers. Something I’d never expect from Sonos.
In my case the click is a soft click (not a thud or a crack or static) reminiscent of a scratch on an LP but at the same level as the music, ie not louder than the music playing and not a low-level click.
It happened on Songbird by Fleetwood Mac at around 5 seconds in. I restarted the track and it was repeatable at the same point. I paused immediately after the click. I went to another stereo pair of Sonos speakers (One SL, in the same group as the Era 100s) restarted the track, no click.
Went back to the Era 100s, played from the start, click at 5 secs as before.
Later in the day I played the same track again, no click. I have heard clicks on other music tracks as well, repeatable at the time but later in the day not repeatable. This makes me think it's something that the buffer is doing, eg loading it incorrectly (ie with the click) into the buffer and then it's repeatable at the time but once that has cleared the buffer it's gone forever.
Some Era 300 people are finding it's linked to high transient sounds but in my case the clicks have occurred at times when the music is at a fairly gentle level. Of course, there may be more than one fault occurring here!
I have the speakers on all the time and I've never heard any clicks, static or anything from them when they are paused (but not muted). The microphone switch at the back is down (which I believe is off).
I do hope it's a firmware issue, because on the other thread there seems to be a lot of people returning Era 300s for replacement, only to find the replacements have the same fault, which is such a waste of the planet's resources.
Come on Sonos - admit there's a problem and tell us what you are doing about it. Perhaps once it's fixed you could offer users a complimentary Combo lead (for those who request one) in recompense for the customer having to do the beta testing on your new product...