I gave up on subs, maybe it’s in my head but I convinced myself they only blended with my speakers at a specific volume! I even got so bad I bought one of those velodyne subs that came with a volume remote, still no joy, but that’s my insanity.
I was offered a pair of Dali Kore’s for a really hard to refuse price, but refuse I did because I figured they’d overload my room, damn.
I heard the KEF ref 3’s in a few rooms at axpona and if anything I thought the mids needed to be tamed most in those little rooms.
Idk of any math calculations to predict bass response, most of the time it’s room nulls I get. You state to listen at fairly low volume so you ought to be with any practical choice