A TV or Roku remote can only control the volume on the speakers in the home theater setup. It cannot control the volume on any grouped speakers.
Just curious… where did you place the pair of Era 100 speakers? Do you notice any delay on those speakers when playing TV audio?
First of all you can only connect one set of surrounds to a Sonos soundbar. Your remote will work with a soundbar to control the volume of components directly under its control (sub and surrounds). You can’t force the system to do something it wasn’t designed to do.
The only way I am aware of, is to use Sonos voice control, or Alexa voice control, to adjust the ‘group volume’ - I’m a little surprised that you do not notice the slight delay/echo effect caused by the extra Era-100s when playing TV audio to the group
. That said, I’m assuming you have not adjusted the ‘TV Dialog Sync’ setting on the Arc Ultra?
The likely reason the TV sound sometimes drops out on the Era 100s is possibly you have ‘ungroup on Autoplay’ set in the Arc Ultra room settings… at least, that’s my first thought.
A TV or Roku remote can only control the volume on the speakers in the home theater setup. It cannot control the volume on any grouped speakers.
Just curious… where did you place the pair of Era 100 speakers? Do you notice any delay on those speakers when playing TV audio?
Hi I deeply apologize for the inordinate amount of time without a reply but let me just say. I’ve been with the system for a while now obviously and no. no delay. With that said I have the ultra Ethernet Plugged in as well as the second rear sub. — edit 
, I forgot to mention the small caveat. With My set up as described there is occasionally a half second delay when something starts but that is atypical, And is resolved within a second or two. —
With regards to positioning. The arc ultra sound bar in the center obviously and the two era 100s to the left and to the right of the television about 4 feet away. In the rear are two surround sound Era 300s. And an additional sub. It is important that the two eras are in a different group because then they can be stereo.
Let me just say that this system for the ultimate immersive set should 100% be sold with the two era 100 I could not imagine my system without those two Side front …
Sonos read what I said. After over a month of Using this set up it is an adequate setup without the Additional era 100s.
ITried that same setup with a pair of Move speakers in stereo. There was a slight delay that can be eliminated by moving the TV Dialog Sync slider in the Sonos app, but then the TV lip sync will be off a bit. Never Enough Tech tried this with 4 Era 300 speakers.
https://youtu.be/yNQsHL6l8NY?si=xzxWaP3BfjqmAECQ
I would really hate the fronts being out of sync with the rest of the set while watching TV. I understand different people react differently to this, so if it works for you, go ahead!
I disagree about sonos selling such a set up though. The Arc isn't a center speaker so the side spaakers would just to stereo, doubling the outside spakers on the Arc. That, and the delay associated with such a set up, would not be up to Sonos standards.
To the OP, just FYI: The grouped Era 100’s in the front aren’t playing the front Left/Right channels, they are playing all channels; surrounds, Atmos, fronts, and center, downmixed to stereo. Which means the actual surround and Atmos signals are compromised, ruining any positional/directional queues and screwing up the Atmos effect. In addition, the soundbar is still playing the front L/C/R, along with the downmix in the “front” Era 100’s, muddying up the front soundstage that is already compromised because sounds meant for the rear and above are mixed in with the sounds meant to come from the front.
Also, no matter how you adjust it, you are going to have a delay, or lip sync problems. In short, it’s a mess, and not even close to how the soundtrack was supposed to sound. More speakers does not mean better sound!
I would really hate the fronts being out of sync with the rest of the set while watching TV. I understand different people react differently to this, so if it works for you, go ahead!
I disagree about sonos selling such a set up though. The Arc isn't a center speaker so the side spaakers would just to stereo, doubling the outside spakers on the Arc. That, and the delay associated with such a set up, would not be up to Sonos standards.
Not just doubling the Arc. The “fronts” are doubling all channels; surrounds, Atmos and front L/C/R (and attempting to play the .1 sub signal, too).
