Devialet Phantom - Network Logic?

[struts]

Thank you very much for that very comprehensive answer! 

1. I don´t think that they have a peer-to-peer network as it would show up when I do a network sweep in the Unifi System (it even detects networks of neighbours 500 meter away, as we have 3 AP´s outside). If they don´t have any other mumbo-jumbo protocall but that seems less probable. 

2. The PLC might be one of the answers but I´m still a bit sceptic about that because I do have very low wifi coverage in our big bathroom thats clad with quite thick granit tiles...and I tried to have a stereo setup in the bathroom with the Phantom II´s but that never really worked great, which would be an indication of poor WIFI reception and no connection via PLC. 

3. It might just be the unifi-system that doesn´t show network traffic the way I thought it did....

4. Or it might just be me beeing a nerd with too much interest in how it works instead of spending time enjoying THAT it works

1.  I am always loathe to trust religious belief over my own observations so I would agree, I see no evidence of any peer-to-peer communication between my Phantoms.  Does make me wonder where I got that notion though.  One explanation is that inter-pair Wi-Fi communication was peer-to-peer under DOS 1, i.e. back in the Dialog era, but not under DOS 2.  I seem to remember testing it and seeing an up/down traffic pattern on the two speakers that would support it, but my memory is foggy.  If so I probably posted about it here, will have a look and see if I can find it.  Another explanation is that I just dreamt it up!  

2.  Have to admit that your Phantom-equipped, granit-clad "big bathroom" made my day.  Classy!   But PLC should work fine on one spur - unless you also have some very noisy units on it (no, I'm not asking).  Might be interesting to test by forcing those Phantoms onto PLC in the app and seeing how it works (with and without the jacuzzi).  Maybe you already have?

3.  True, although mine is showing traffic "down" to both and "up" from neither* which would seem to be difficult to misinterpret.  Could always be a bug in Unifi of course.

4.  Definitely - especially with a bathroom like that!  

* That would seem to differ from your observation @diamar.  Both of my Phantoms are connected to my AP and I am seeing similar volumes of downlink traffic to both.  How are yours connected to your switch?  Wired or wireless?