Hello @Zab,

Welcome to the Sonos Community and thank you for reaching out with your set-up question.

Home theater set-ups, like any speaker placement, are going to be in inherently subjective.

If you are able to provide a picture of your space, we may be able to offer better specific guidance for your location.   

Please see attached.  Any insight is greatly appreciated.

Interested in any insights, particularly if it’s even worth going with the Arc if given my room, I’ll be losing Atmos functionality or other surround effects.

You won’t really get surround effects with the bar alone because you don’t have walls for the bar to bounce the sound off of (I don't think it can bounce from that small portion of wall back behind your seating area because there is no angle to do that).  Your ceilings are fine for Atmos height effects.  Note though that surround and height effects with sound bars are very limited without rear/in ceiling speakers.   They are never as good as true dedicated speakers.  In your setup, it would be great if you could find a way to wall mount rear speakers (or put speakers in your walls).  I know that may ruin the aesthetic to have speakers on the walls, but in wall speakers, or ceiling speakers, might work.  But there is no soundbar that will really give you that surround effect.  That said, the Arc is wide and will give you really good stereo sound.  It looks like it should have bigger, more powerful drivers than the soundbar you have now too.  You would want to mount it lower than the bar you have now (more space between the Arc and the TV).  That may mess up your wallpaper, so you’d probably want to raise the TV (if you don’t want to make visible holes).

Thanks for the insight ewoloff.  I’m considering two Sonos One SLs on stands directly behind the couch.  I guess that’ll round off the surround issue?  Do you think I’ll get any Atmos effect?  Hoping some since the ceiling is of average height to bounce off of.

You should get some height effect.  Don’t expect anything incredible, because it’ll never be like dedicated in-ceiling speakers.  That’s not a knock on the Arc but just all soundbars.  Only so much you can emulate.  I will say though that the Atmos trailers sound awesome on the Arc.  There is definitely some height effect but the front spacing is also amazing. 
 

With One SLs, the bar won’t even attempt to do its own surround effects (surround sound will come out of the Ones) so you’ll be all set there. 

@Zab 

Thank you for including pictures of your living room setup, I think @ewolkoff has offered some very sound feedback for your space.

I would be only slightly concerned about the placement of your Sonos One SL rear surround speakers.

Would you be setting them in the opening in your wall or mounting them in the corners behind the sofa?

I was actually going to buy the Sonos stands and place them right behind the couch (on each corner) with the base of the stands tucked under the couch as shown in the following image.

What may be lost in the images of my living is that there is about a foot and half of space between the back of the couch and the half-wall.  As an FYI.

@Zab 

Thank you for the additional information. 

That should work out well for you then.