I have no subwoofers at all. Well treated room with outstanding setup, no need. Tried them and sold them…..
Not all subs are created equal and not all can correctly integrate. Unless you have speakers that can get to 30Hz and not screw up 300Hz doing it, subs add a realism out of all proportion to the added Hz.
As a composer friend once said upon hearing my system "Those little speakers aren’t putting out all that gorgeous bass?!?!?!?!?" ... "Every other subwoofer I’ve heard just boomed."