@elliottbnewcombjr
A successful speaker designer has told me that in his opinion two subs operated in stereo can work very well. Others here enjoy the Audiokinesis Swarm type bass systems using 4 (or more) subs summed to mono. I can say my two high quality subs located at the front of the room and run in stereo are vastly superior to when I used one sub only. I would still like to try one or two additional subs summed to mono and located in the back of the room. I believe one reason this works well in my system is that my stand-mounted acoustic suspension speakers have dual 9-inch woofers and run reasonably flat to about 40Hz so I can roll the subs in at a relatively low frequency.
I'm a big fan of mains with no ports, full range for large rooms, or, smaller mains with no ports, with stereo pair of front facing directional subs (self powered) for smaller rooms.I too like sealed (i.e., acoustic suspension) speakers and believe, in general, the bass roll-off and low frequency distortion are improved over ported (i.e., bass reflex) designs. However, as with anything, there are excellent and not so good examples of each type.
A successful speaker designer has told me that in his opinion two subs operated in stereo can work very well. Others here enjoy the Audiokinesis Swarm type bass systems using 4 (or more) subs summed to mono. I can say my two high quality subs located at the front of the room and run in stereo are vastly superior to when I used one sub only. I would still like to try one or two additional subs summed to mono and located in the back of the room. I believe one reason this works well in my system is that my stand-mounted acoustic suspension speakers have dual 9-inch woofers and run reasonably flat to about 40Hz so I can roll the subs in at a relatively low frequency.