It's a matter of not turning it up to loud.
In the next room it sounds tonally accurate.
Open doors on the listening wall at both ends
In regard to how this would look.
My daughter has a great room in a recently built house - but it's 10 ft ceilings and things open up into a modern open kitchen floor plan.
Older homes can't pull that off so well.
I am stuck with 8 ft ceilings which might make a larger room look more "cave" ish. and constrain the sound further back.
My friend has a split level where he renovated the downstairs - knocking out a bedroom and created a 30 x 18+ space. His restriction was a 7' ceiling - but it sounds great in there and opens up onto a lovely backyard and pool. Incidently his house is where we played the Ulysses and they sounded wonderful with the larger depth.
Don't get me wrong - I am getting great sound from my system
but I know with those speakers going from 9 ft to 11 ft or greater away really allows them to sing.
My neighbor and friend is a contractor and has done all my home remodeling.
One option is to add a nice finished central beam and wall frame to cover the room transition which also would allow you to quickly and effectively put a wall back up later.
just a thought