tenant or your own space below: nix to downward firing bass drivers or ports.
nix to wanting a lot of bass when the space below is used, thus tone controls might help when those spaces are occupied, out of circuit when below is unoccupied.
isolation decoupling speakers from floor probably needed. you could start with a set of 2x2 isoblocks. many swear by townsend iso platforms.
I've installed corporate fitness centers with occupied space below: add separate 'floating' floor on absorbent blocks, small ramp up.