Yes, you would just group your Arc Sonos room with the other rooms.  However, the Arc will play audio immediately to stay in sync with the TV.  Other rooms will be slightly delayed for buffering reasons.  Not an issue if the other Sonos rooms are truly in another room, but will create an echo effect if the Sonos rooms are actually in the same room as your Arc.

Thank you.  I really wanted a system that’s completely in sync.  I appreciate your advice.

Unfortunately, the lag is needed because sending the signal to other rooms means it needs to go through walls, floors and ceilings, and the less latency, the smaller the buffer, and the more those walls, floors and ceilings can affect reliability.  Sending a signal to a Sub or surrounds in the same room doesn’t have those problems, so it can use a direct 5 GHz signal which has trouble penetrating walls, floors and ceilings, but has low latency.

When I say it’s out of sync, I’m talking about less than a second.  For example, if you want to have the big game playing in a bathroom and outside as well as your main living area, you won’t notice anything. And don’t forget the speed of sound isn’t instantaneous either.

To find a more in sync solution, you essentially have two options.

1 - Buffer at the source for both audio and video so that both can be delayed equally.  This is pretty much what you get if you were using an AppleTV and airplay, as I understand it.

2 - A wired solution, or partially wired solution.   An old  style whole home system where every speaker is wired to the same amp would be very near sync.  As well, you could wire several TVs to the same source via HDMI, with each TV having a Sonos home theatre room connected.  In that case, each room plays immediately with the TV separately, not  grouped.

Thanks Danny.  Previously we had a speaker switch connected to Zone 2 of an AV receiver which would play any source throughput the house via the wired ceiling speakers.  This was great but there was no volume control for each Zone.  Since moving I’ve looked at Control 4 but this is prohibitively expensive so now I’m considering Sonos.  We’re in the process of building an extension so I don’t want to miss the opportunity of installing a decent multi room system but I don’t want to make an expensive mistake!

To be honest, unless you have multiple speakers in the same room as the TV, you don’t notice the lag.  I routinely play the TV sound in the bathroom in the morning and don’t notice it, and the bathroom is only 10-12 feet away from the TV.

Thank you.  That’s reassuring.  

Even with all speakers connected to the same receiver, you can experience awkward delays. Audio is pokey, traveling at about one foot per millisecond. Consider a 30 foot room with speakers on opposing walls. Listener ‘A’ standing by speaker ‘A’ will claim that speaker ‘B’ is delayed by 30ms. Listener ‘B’, standing by speaker ‘B’, will have the same opinion about speaker ‘A’ -- yet listener ‘C’, standing at the midpoint, will claim that the speakers are synchronized. All three observers will be correct.

With respect to distant Grouped rooms where it is not possible to hear more than one room at a time. The TV sound played in a SONOS Group will be delayed by 75ms with respect to the video in the main surround room. This delay would be significant only if you were attempting to view video along with that audio in the distant rooms. 

Note that there can be issues with video synchronization too. Multiple cable boxes will not necessarily stay synced with each other. A bar in my area has multiple TV’s, each with its own cable box. If all of the cable boxes are tuned to the same channel, the TV’s will drift out of sync over time -- by several seconds if you watch long enough.

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Note that in-wall speaker Volume controls are available. If you use these, rather than a simple switch, to connect multiple pairs of speakers to an amplifier, individual Volume control is possible.

Thank you for your help/advice.

And in case it’s not clear, if you’re listen to streaming audio, every room is buffered the same and plays in sync.  TV audio is the exception since you’ll want the audio in the TV room to match the video.

I have never had an issue with the multiroom sync for TV audio.  But to be fair, I rarely group rooms with TV audio, and when I do, I usually have multiple TVs playing in sync like the #2 case I mentioned earler.  For music, I group rooms almost all the time.

Yes, this is why I went through the effort of linking several TVs to the same source, cable box in your example.  They would never be in sync for cable, and you certainly couldn’t manually sync up steaming video sources.

I’ve seen this with sirius xm too.  I’ll be listening to something on Sonos, then get in the car and listen to the same station on satellite, and it’s several seconds behind.  That’s not counting the time it takes to walk outside, startup the vehicle, and tune in to the station.

Danny, just to add to that…..

I’ve had issues recently with the Hulu app on my Apple TV delaying the audio slightly, particularly on American football games.  It’s annoying in the TV room, but I’d never notice in another room (kitchen, for instance). 

Definitely not a Sonos issue though….if I reboot my Apple TV, it goes away. For a while.  Not sure if the problem there is Hulu, or Apple TV, just know it’s not Sonos. Haven’t done enough testing to figure out whether it’s app based, or OS based. I don’t seem to get the same issue on other programs, though, so I’m still trying to make it make sense in my mind.