Not technically, but you certainly should check what type of signal is being sent to your Arc.

Sonos doesn’t support an option to allow both the Arc (as essentially a center channel) and outboard front left and front right speakers. 

Is your Arc mounted with the end speakers free to radiate sound or is there something in the way?

How far away from the Arc do you sit and are you centered on it?

Our Arc is better than our Beam at this and we are quite happy with it.

Switching to an Amp and non-Sonos speakers would let you widen the sound but if you go too wide you’ll end up with an audible hole in the middle.

Thanks for the replies.  I sit in the middle, about 12 feet from the Arc.  The Arc sits about 6” in front of the screen and there are no obstructions from the side speakers to the walls.  I get great separation from the rear 300s, but in front, everything just comes at me from the front.  Too bad you can’t adjust the side-firing speakers.  I think that would solve my issues. 

Is it possible that Sonos would make the Arc’s side speakers volume adjustable or make it possible to add front speakers?

Possible? Of course. Likely? Debatable..and both sides of that debate would be ‘right’ until such time Sonos actually announces it. I wouldn’t recommend holding my breath, but then again I wouldn’t be saying ‘never’ either. 
 

Ok, thanks.  I just wondered if it was even possible as a software update.  I also have a Sony HT A9 setup and although the sound quality isn’t up to Sonos’ par, I do enjoy the real spacial effect that it has that Sonos doesn’t have.  The addition of Sonos fronts would make it perfect.

Not an engineer, so take my ‘sure’ with a grain of salt. I don’t have any inside access as to whether it really is possible, just going with the ‘generic’ sure there. Probably raising hackles on real engineer’s necks by doing that.
 

The simple fact is, none of us on the outside really knows why this hasn’t been done already. My imagination suggests it’s not ’easy’ to do, and there are some sort of limitations (hardware?software? Bandwidth?) that are involved. 
 

This kind of feature request has been going on since the original PLAYBAR was released, and there’s been zero movement on it, which is why I suggest not holding your breath. I suspect if there was an easy way to make it happen, and it would sell X thousand more speakers, it would have already been done. But then you get into the whole concept of a soundbar as a center speaker, and not all three front channels together. Which implies more CPU to split out those channels, more bandwidth to transmit them, and therein lies to the potential of ‘if this were to happen, we’d get new speakers, and not be able to use the ones already out there’…which could be limiting on sales, and raise the anger level of the community.

Lots of things to consider , from a product manager perspective. And any of those could be the reason, or at least part of the reason, that it hasn’t yet been done. 

Thhanks Bruce. Great explanation. Still, I’d love to see it happen.