I have a SONOS ACE and I use it only with the usbc to jack 3.5 cable because I don't want wave on my head.
I test it with an electric field meter : despite the led is white, the headphone always emits in bluetooth (10V/m instead of 0.6V/m).
This value is very very high because the bluetooth of my smartphone is off : The headphone ping in continuous to search it.
If I turn on the bluetooth with the cable and I use the Sonos application : the value decreases at 3V/m but it's again high.
I don't have this problem with my old headphone from an other mark (0.6V/m with cable, it's the environmental noise).
There a solution to really turn OFF the bluetooth or it's a software bug ?
Sonos can confirms this problem ?
