I have no subs ATM.
Currently I sit about 12 ft away.
that's the thing even at normal moderate levels with Music I just feel missing that little more bottom end. Maybe, I can boost that bass a bit.
Currently , I have a AVM30 so no ARC ( Audessy )

When I have the subs they will more than be enough for the room. I am the biggest the room will be is 17 x 23 x 9. if I build on the addition. I have a rec room area now, currently my daughters entertainment area. She's off to university in two years, this was going to be gutted and I was going to build a movie room there. However, it is only 12 x 18. So a bit too small and being 12 x 18 x 8 not the ideal dimensions. Pretty sure the three subs I am looking into will be more than adequate.

The bottom end punch I am talking about is in 2 vh and music listening.
I am not sure the levels, obviously for movies I am louder than normal tv levels.
music well it is louder than movies levels. And occasionally I like to turn it up abit more, but that's rare

Anthem MRX520
M5HPv4
VP160HPv4
QS10v4