My main towers are 15” Altec 604C coaxial.
My sub is the floor firing 15” Velodyne.
Imho in order to project authority, you need to move a lot of air.
There is no substitute for cubic inch or in this case surface area
After listening to quite a few speakers, my conclusion is that if you want large enveloping soundstage, you need a lot of drivers.
I once had a speaker with two 12in. drivers and the soundstage is just floating in the air. None of my other speakers could do that.
Currently I have a pair of Thiel CS2.4. It is a very good speaker but with small drivers there is really limitation to what it can do in term of soundstage size. I really miss that.