Not sure what that person was referring to. You can “always” group your home theater room with other rooms. In the other rooms, you’ll only get at best a stereo signal, and there will be an approximately 75 millisecond delay between the two rooms, of course.

As to your cutting out issue, I suspect this is due to some sort of wifi interference  affecting the signal. The input from a TV is a much “denser” or higher bandwidth signal than a normal streaming music signal. This means it’s much more susceptible to that interference. I’d be reading through that linked FAQ for potential solutions. 

In general, if you’re having that sort of interference on your normal wifi, I’d concur with your expectation on the BOOST….although a saving grace there may be the fact that the BOOST can be set up to use a different wifi channel, which may not be affected as much by the wifi interference. 

While it doesn’t sound like a duplicate IP address issue (if it was, all sources, not just the TV would be affected), there’s no reason not to refresh your network by unplugging all Sonos devices from power, then rebooting your router. Give the router a couple of minutes to recover, then plug back in the Sonos devices.

One thing that I would definitely try is a different channel on your router. Use 1, 6 or 11. It’s entirely possible that if the interference isn’t coming from inside your home, it’s coming from outside. In the last couple of years, I’d had a new neighbor set up their router on the same channel I was using, and it caused a bunch of hard to diagnose issues for me….until I switched the channel my own router was using. Fixed it :)

Thank you for your fast and very useful input!

OK, so a little more history….my internet provider has sent round 2 engineers in the 10 days as I have told them of this issue.

I am on fibre to the building with the lowest package (150mb download and 30mb upload). I can upgrade easily to 314mb, 500mb and even 910mb if I want but didn’t think it would be necessary to run Sonos successfully. I run an 8K 85 inch and don’t see issues running at 8k on YouTube.

The internet engineer also commented wireless is maxed out at 500mb on the BT Hub 2. So pointless to upgrade pass this if I was to consider.

In the last 3 days I have installed a mesh system which was advised to be tried also by my internet provider. No improvement. 
They have walked round the entire apartment which is fully open plan with no walls only a mezzanine and no blackspots are present. So it cannot be lack of coverage.  

The internet engineers have said they cannot see any issue with the network and point blame at Sonos or the software for not working correctly, they do not know how Sonos works or is configured.

The first time I spoke to Sonos, I submitted diagnostics and they said right away it was due to bandwidth. 
 

Sonos customer service agent 1 of 3 originally advised to change channels to 11 on the router and said 9 times out of 10 that will solve it. There was no mention of not being able group and play TV audio outside the 5.1 channels. It’s only today customer service agent #3 told me different and said that is why I am having issues. It cannot be done.

I’m confused now with this conflicting info and being told different.
 

Moderator Note: Released from Spam filter at 20:06

When you Group Rooms, the first player in the Group is the Group’s “Coordinator”. All of the Group’s traffic passes through the Coordinator. When Grouping TV audio, obviously BEAM is the Coordinator. 
 

If BEAM is wireless and there is wireless interference near BEAM, BEAM could be a not so great Coordinator. As a test, is there any difference in performance if you make BEAM the Coordinator while playing music vs one of the other players being the Coordinator?

In terms of WiFi setup, use 20 MHz channel 1, 6, or 11.

Hi. I think this should work OK.  Please would you confirm whether you wired just the Arc or all of the HT speakers?

Please also confirm that you are building your groups starting from the Arc. (I am not sure there is any alternative if you  are playing TV sound.)

Have you tried changing the Group Audio Delay setting in the Arc Settings?

The ARC is wired in with the arc cable provided. 
 

Group Audio delay is on LOW when just checking.
 
see image how it is:

Hi. Sorry I meant wired to the router. Have you connected the Arc by Ethernet to your router?

Have you tried increasing Group Audio Delay?

No haven’t tried arc on Ethernet.

just been testing Group Audio delay and getting issue still on LOW, MED, HIGH only. MAX shows no issues with cutting out whatsoever but has big delay obviously. What does this teach us? 

It teaches us that your network needs more buffering in order to play TV audio smoothly across the network.  For many users it is a solution in itself  because they cannot see the screen when listening to the other speakers 

@John B

What do you mean exactly ‘your network needs more buffering’ ?

Is there something I can do?

also.. my second reply after @buzz in the thread has gone missing. After editing it said it needs to be approved by an admin. Is this normal and will it return? I made some important points there 

Hi. For the avoidance of doubt, I am just a fellow user not a Sonos employee. 

But your post has probably gone missing because the spam filter has rung a false alarm. This won't be content modration and hopefully the post will reappear. 

There is nothing faulty with your network. But for some reason the audio data packets are not arriving fast enough for the grouped speakers to assemble, decode and play the music smoothly in the buffer time allowed.

As an experiment, could you wire the Arc by Ethernet to your router?. 

 If that is impractical please connect one of your other speakers, moving it if necessary.

Wait a few minutes then try it with various Grove Audio Delays

I did wire (Ethernet) one of the One SL to the router today and it was still experiencing the same cutting out on that SL speaker. 
Tomorrow I will try connecting to the Sonos Arc with Ethernet with the arc lead still connected.  

Was the One SL you wired one of the surrounds?  I should have specified never wire a surround or Sub.

No it was a new one I purchased today. Not part of the home theatre 5.1 group. 

After wiring a device you need to give it some time to reconfigure.  Check that all speakers except Move and Roam have WM=0 in About My System. 

Ok so update:

I have added Ethernet cable from router directly into the Sonos Arc and issue resolved 100%. No cutting out on the speakers outside the ‘Home Theatre’ speakers!!

So…does this mean I can buy a Sonos boost and it will do the same thing? 
 

I did try an Ethernet cable into one of the speakers outside the Theatre 5.1 set up and it didn’t resolve the issue. 
Does that make sense? Or maybe I didn’t leave it plugged in long enough? But pretty sure I left it in for a good 5 mins or more. 

As long as you can wire one of your main speakers to Ethernet (not Sub or Surrounds) a Boost will do little for you. It was discussed earlier that it looks like the Boost may be being discontinued.

I’ve found with my router I get a more stable Sonos setup by assigning static/reserved IP addresses and wiring as many Sonos (main speakers) as possible. A full Sonos and network reboot after assigning the addresses should get everything in sync.

Just to add… What amazes me more than the people on here willing to help and incredibly knowledge, is …..being told by Sonos themselves that what I am trying to do is not possible and Sonos is not designed to play audio on other speakers outside the Theatre 5.1 set up.

I am shocked! 

Users of the product often have more knowledge than people who are paid to answer phones, and frequently work more from a script than first hand knowledge. That’s not unique to Sonos in any way. 

A Boost will have the same effect as wiring to another speaker, not to the Arc itself.  So that doesn’t look promising.  To make sure it has gone over to SonosNet, check that all your speakers have WM=0 in About My System.

Because you build your group from the Arc, the Arc acts as Group Coordinator (GC).  The stronger the signal at the GC the better the performance of the group. It should be OK wirelessly, but maybe there is some local interference which is scrambling it

Could you go back to wiring one of the other (non-Sub, non-surround) speakers and put the Arc back on wireless temporarily?  Check the WM=0 thing.  Experiment with changing the SonosNet wireless setting and Group Audio Delay.  If you can’t find an acceptable solution there is one more thing we can try to help us see why it’s not working perfectly, so please post back either way.

I think it is fair to say that Sonos isn’t designed to play TV audio in other rooms, and ir is sometimes more problematic than grouping for music.  I think the very existence of a Group Audio Delay setting is an acknowledgement that Sonos wants to make this possible, but that it can be problematic and imperfect.

@John B 

Thanks for your input. I will try these things.

Worst case I will put a Ethernet directly into the Arc as this has solved the issue and can fall back onto this as a solution. 
The Sonos is wall mounted at one end of an completely open room and although it will be pain to feed Ethernet into the stud wall it is 100% doable.