[doggiehowser]

PS Audio recently moved factories - and as a result, Paul has been (like a kid in a candy store) designing his best music room.

Have a look at some of his planning videos on YouTube which he talks about simple things to do when building a room.

45 angled corners (in place of expensive bass traps), slightly tapering walls (preventing parallel walls/ceilings), and using crown mouldings (?) at the edges where the ceiling/walls meet.

I would also add
- instead of a thick, plush carpet, go for a more regular (easy to maintain) carpet but fit a really thick underlay underneath that gives you a bit of bounce for sound deadening.

I don't know about the Futura Amatis but the Amati Traditions need a fair bit of space from the walls (side and behind them) so be prepared to have them fairly into the room. I also use a fair bit of toe in (almost firing to the sides of my ears in the main listening room)

Putting them in the room does affect the path of a projector (and size of the screen) - if you are still considering it ... I know you mentioned the 84" TV

Once you have placed the speakers, you kinda have to sit at least as far back as the two speakers are apart (if not more.. I prefer long isosceles) and still have enough room behind the listening position.

As for the room within a room - i think the penalty isn't that much maybe about 6" on each wall but I'd only do it so as not to affect the rest of the house (or neighbours if they are really close). Otherwise, I would just worry about room acoustics.

Also - seems a shame not to use Atmos if you have an RS20 from DataSat!

I'd definitely do 5.2.4 over 7.2 or 7.2.2