I never thought of using the IKEA range of speakers for surrounds. You have given me an idea for my TV room that has just an ARC at present, much cheaper than using Sonos own speakers.
I very much doubt Sonos streaming can support 5.1 but your using AirPlay not Sonos streaming so that is definitely limited to stereo.
From the horses mouth.
What about surrounds for music?
Sonos doesn’t currently support any 5.1 music formats, but you do have settings for music playback when using a Sonos 5.1 system. For music, you can set your system to play Full or Ambient sounds out of your rear speakers. This setting is found and explained in the article here ‘Set up Surround Sound with Sonos Home Theater speakers’.
No it doesn’t support 5.1 for music period only for video content over the network. It may or may not work via HDMI but you won’t get 5.1 out of a fire Tv via Roon anyway only via HDMI from a pc running the core or Roon Bridge or a Roon Ready device that support 5.1 over the network.
I have a number of friends who use them for surrounds and think they are great for that, just not as good for Music.
I am thinking of buying the basic lamp to replace my bedside Sonos 1 and put another one on my wife’s bedside so I can get stereo in the bedroom.
I also wish I could have music in 5.1 on my Sonos Arc set-up. I listen to more concert’s now and besides some DTS HD issues (where it comes through as multi channel PCM) it has been great.
Good Atmos soundtracks are Amazing and I will be buying more of them.
What about from Plex, though all my music is recorded in stereo. I think I need to look at ripping my multi channel SACDS for something that Plex can use as I do with ally concerts where I store all the track’s in original format.
Could make it interesting, though no good if you got an Apple TV, as it cannot pass through the original tracks for some reason. I ordered a new one before watching a review and decided to stick with my Shield TV. I cancelled my order before shopping