If a feature is important to you, check before you buy.

What did you want them to check?

Before assuming they haven't done their research and it can't possibly be a different or, heaven forbid, a Sonos issue, think that maybe they did and it should work?

To the OP, check if this helps?

Can you be a little more specific? In which use case? Playing music etc via Bluetooth or streaming video and swapping from Arc? Don't expect Ace wear detection to halt video playing, but do expect it to halt music etc through an app.

Hi I just using them to play music from spotify and never detected the sensor when I took off from my ear the headphones. It happend the same when i received a call they did not answer call automatically when I putted them on.

Return them. Sonos are promising many things with their sales spiel and letting customers down big time, like the promise of a seamless easy to use whole house wireless speaker system. Do not spend hours on the phone trying to rectify something that you were told would function as described, send them back and move on to something that works as you expect straight from the box.

Check that the ear pads are on properly and the sensor lines up with the sensor port in the ear cup.

Simply removing the headphones will not tear down the Spotify connection. You need to power down the headphones. Spotify will then transfer back to the Spotify App. A while after removal there will be a timeout, but this will probably be beyond your patience.

I doubt that the headphones will ever work as you prefer.

If I’m listening to music through my Android phone a call will replace the music. Note that this is something that I only use for testing purposes and don’t care about. Therefore I am not aware of potential timing issues that may be important to some users.

The headphones will manage two sources nicely. In my situation there is a PC, an iPad, and an Android phone vying for the headphones. The “number three” source may have disconnected and need to be reconnected, but then one of the other devices will become “number three”. Over the weeks, (updates) this has become less of an issue, but I sometimes need to slap something in order to re-establish a (“number three”) connection.

@Cesar SancheZ,

I would suggest trying what @Stanley_4 mentions… remove the magnetically connected ear-pads and re-seat them. I would also toggle the wear detection off/on again in the Sonos App and ensure the Ace is running on the latest firmware update.

To get the wear detection feature working for answering incoming phone calls, you need to enable that feature in the App too (if not done already), as that option is set to disabled by default.

@Cesar SancheZ,

Ken uses his headphones more than I. 

Maybe one of these options will help you.