Hi @User77023
The Arc when not used with Sonos surrounds will employ it’s side speakers (left/right end) to bounce sound off adjacent walls to help with the surround effect. The upward firing speakers also contribute in this scenario.
As with any Dolby Atmos AIO speaker the more rectangular the room with 8 ft. ceilings the better the 3D effect. My room measures 13ft wide x 20ft long x 8ft high. Arc is 2.75ft from wall, 2.5ft rom left wall and 6.5ft front right wall. Seating is 12ft from Arc.
I don’t know what the maximum distance is for the Arc to reflect sound off walls. I’d say if you’re at great distances_left/right_you might consider adding surrounds.
FYi...The Arc has no rear firing speakers.
My complete setup consists of Arc with Sonos sub and surrounds.
Thanks for the response. I suspect I will need to get a pair of play 1 for rears in that case. It's not a simple rectangular room