volume lowering

Do the volume numbers in the controller get smaller or is it just the audible levels?

Audible levels go down so I have to increase the volume

If the numbers aren't changing that probably rules out some common issues.

Wait for it to happen again, send a diagnostic within a few minutes and then when you have time call Sonos to have them look at it. 

If im having to increase the volume doesn't that mean the numbers are increasing? Im was thinking it was a feed issue, but after calling sonos the speakers are more responsive and slowly lose volume over time.

Over the years there have been heated discussions with respect to how loud the sound should be at a given number. There is a large body of the public that correlates “powerful” with low numbers for high output. These individuals want to purchase “powerful” units. Unfortunately, if the system is “loud” at low numbers, it is very difficult to control at low Volume and there are then lots of complaints that “1” is too loud. From time to time an update will scale the numbers differently in order to give better control at low Volume and there will then be outrage from the “powerful” crew claiming that their unit is now less powerful when the actual output at full Volume has not changed.

There is another dimension to “loud”. As the Volume is increased beyond a certain point, amplifiers enter a high distortion mode and we have been conditioned to accept this as “loud”. In my college apartment we could run, still with low distortion, at levels where verbal communication was very difficult, yet guests would approach, hands  cupped, yelling in our ears “turn it up” because the system did not seem “loud” yet. This same crew in another venue, using a dreadful low power compact unit, was satisfied that it was playing “loud” while conversation was easy.

SONOS will sometimes be accused of being low power because, by design, it will not enter this high distortion mode.