Can I group a pair of Fives as front left/front right with an Arc Ultra system Home Theater System?

In a word: No.

The soundbars do not support extra “L/R” speakers. If you Group a stereo pair of speakers with a soundbar, the extra speakers will not be incorporated with surround processing and there will be a time skew. When playing a music source the Group members will be time aligned.

Are you 100% on that after the latest firmware release?

How doe Sonos decide what’s music source and what’s not? Stereo PCM? Dolby 2.0?

Yes, he is sure.

Technically, it isn’t music source, it is input method. The TV input versus LAN connection (streaming). The TV (digital) input has no idea if it is receiving music or something else, but that input is treated as a separate process, and only allows bonded devices to that room to be synchronized.
 

As soon as you take that data to a second ‘room’, the normal input delay is applied so Sonos can play the data in sync in all other rooms. When using the LAN to stream data, that delay is already paid on the input, and all ‘rooms’ will be in sync. 

That would be a major shift in functionality that Sonos would officially announce, rather than bury in a firmware release.  So yes.  99.9% sure.

If the source is the TV, coming through the HDMI or optical cable, than is TV audio.  Every other is referred to as a music source.  The format and quality of the audio played isn’t relevant in that regard.

ah, so any device connected via HDMI is considered “Not Music” even if its a DVD player playing a CD? Or is it only the eArc HDMI considered “TV”?

I was referring to HDMI cables, not HDMI as a protocol.  In terms of audio protocols, your TV is going to connect via eARC, ARC, or an optical audio signal.  You can’t connect your soundbar to a DVD player directly, as that an HDMI signal, not eARC or ARC, and Sonos can’t ‘read’ that audio.

As ​@Airgetlam pointed out, it’s more accurate to think of it as the input source rather than the type of content played.  It’s just common vernacular to refer to anything coming from eARC, ARC, or optical source as ‘TV audio’, and everything else as ‘music’ as this is the case most of the time, and the way people think of it.  

Regardless, the answer to your main question is still no.

If the audio is played into the Sonos environment via an HDMI input (regardless of what that audio might be), a short delay will occur. Playing that audio to other components via grouping will invoke the longer delay. Hence the rest of the group is out of sync with the soundbar. 

This. Thanks.

Thanks all for quick answers. So its back to either waiting on Sonos or using 3rd party tool with its limitations.

Don’t hold your breath waiting on Sonos: it’s been wanted and requested for a long time…

Using a TP tool may let you do it, but you’ll still have the time lag issues. Plus, the stereo pair will play all the audio, including surround data and centre channel data. That’s really going to muddle any Atmos effects. 

Since the first PLAYBAR was released, if memory serves, back in February of 2013. 

Interesting. Seems like such a no brainer...I wonder why they are stuck in “Soundbar Centric” world?

I don’t even think of Sonos as “soundbar” I think simplicity, minimal cables, multi-channel audio.

It’s probably not a single line of code, but a complete re-engineering of both the code, and the electronics built inside the devices. 

Not to mention Sonos isn’t a high end company, and probably sees little profit to offset the work necessary, and minimal sales. But that’s mere speculation on my part. 

I’d wager the additional sales in Fives, 300s, 100s would  make up for the investment required…but in terms of customer satisfaction, maybe even greater value.

No data as to the effort involved, so no wager. I’d love for you to be right, as I suspect I was one of the earlier requesters of this…or maybe that’s just what I was thinking, and not posting. Either way, for some of us, it would be a usable feature, for many others, a confusing option. I suspect only the Sonos PMs and programmers know for sure, and they’re unlikely to post in this forum one way or the other. I wouldn’t think the Sonos Forum Moderators would have the details as to why this decision has stood for 12 years. 

Sonos does the market research, so I’m thinking they know the market better than we do.  You could also look to competitors and see that no one else is adding this feature in wireless speakers, which enforces the idea that it’s not as big a market as you might guess. 

I was a 100%  in favor of adding this feature a couple years ago.  Now, I still want it, but not as eagerly as before.  With atmos music coming on, it seems the need for stereo separation in the front is less so.  We shall see though.

That’s not what I’ve seen reading through forums, there’s demand now...and would be new demographic of those with larger rooms who’d never consider a soundbar. It's just software, grouping already does it kinda, just need to figure out the delay issue. It couldn’t cost that much to just add adjustable delay when grouping speakers….this is a no brainer ROI case.

This seems like such a layup to give those that want it an option to buy more Sonos speakers

It’s not just as simple as adding adjustable delay for grouped rooms.  The delay is for buffering in order to allow transport between floors/rooms.  Without the buffer, there is no way to resend bad packets when the inevitable communication error happens.  Even the surrounds/Sub are buffered, it’s just so low that it isn’t noticeable, and it requires a special direct connection, one-way 5 GHz private network to do it.  Whether or not that special network can handle two more discrete channels is something only Sonos knows. 

Also, grouping sends all channels, fronts, rear surrounds, Atmos in a downmix to stereo.  Which is very different from sending a discrete L/R to the fronts and not playing it in the soundbar. 

I’d take full signal to ERA100s or Fives in my setup, in a heartbeat. I’ve got an Arc Ultra middle of a 30’ wall. The center channel is significantly louder than FL/FR. It sounds good but definitely would benefit from separates, especially for music.

I understand what you’re saying...but I’ve read they had this working in Beta at one point and lots of people loved it...but they didn’t release it. maybe they saved it for Pinewood?

Anyway, thanks for all the info. I love my Sonos stuff, I just see the potential here and want Sonos to take advantage. People want all the surround/height channels for moves (Atmos is awesome)...but we want it with as few wires as possible. Even high end stereo is moving to self powered speakers, Sonos should be leading this space.

They cancelled Pinewood.  Why that is, nobody really knows.  But there is the possibility that this type of configuration approached the limits of what the tech can handle, and as such, it was not reliable in adverse conditions. 

Because IMO why take on video and streaming with a $$$ streamer to compete with $25 Firesticks? That was a no brainer cancellation, would have been DOA and is perfect summation of the previous CEO’s strategy. There’d have been some appeal to niche users who wanted HDMI switching and official support for adding fronts...but hardly enough to build significant demand for a new product line.

As for figuring out separates, I hear what you are saying...but reality is adding fronts is no different than adding surrounds, from a technical perspective...matter of fact, surrounds are probably more complicated, given number of channels the ERA300 muxes into the bubble.

Nah, I think fronts was held back for other reasons. If you’re reading Sonos Product People, deploy the feature from Pinewood! PLEASE!

Pure speculation, just like my opinion, and neither one of us knows anything real.  Also, you are ignoring the fact that adding separate fronts is piling extra bandwidth (fronts carry far more information than surrounds/Atmos) on the currently razor thin buffer of the 5 GHz connection.

Again, I don’t think Sonos is relying on internet forums for their market research.  I also don’t know that Sonos really wants to target larger rooms for their products.  The market of folks who have 30 ft front walls and don’t want to wire their speakers can’t be that big.  Not to mention that 5 Ghz communication between speakers is going to be strained at those long distances between speakers, trueplay tuning, etc.  I would be surprised if this is the dempgraphic they want to target.

As pointed out already, the delay isn’t arbitrary, it’s needed.  Even if they ‘solved’ the delay issue by delaying the video as well with Pinewood, they would still have an issue with gaming content.

As I said already, I would welcome and use the feature.  I just can’t bring myself to believe the market is there and that the technology would work seamlessly when I don’t know that’s the case.

Good point about the video delay.  CEC “standards” are very hit or miss, and the number of times I’ve seen an automatic video/audio sync CEC function be successful is exactly none.  They either don’t exist, or they make things worse.  This very well could have been an impediment to Pinewood enabling multiple wireless surrounds, fronts, etc.  Because on its face, auto sync would be the ideal solution to increasing the buffer to allow for more bandwidth.  But if not enough TVs are equipped with this function, and the ones who do are doing it with the usual CEC “standards”, then what’s the use? 

And that’s not even taking gaming content into account, which is another great point.

This code is still working on the speaker firmware. While the Sonos app won’t allow you to do it, you can set up l/r front surrounds with a third party IOS app.  This is unsupported by Sonos obviously. DM or check r/sonos for more info.