I have been running the SHL5+ Anniversary version since May 2018. My room is 18’ x 12’ and they suit it very well. In my opinion they seem an ideal fit for that sort of size room. Phil is spot on in that they need to be away from walls, I found about 40 inches from the rear wall works well in my room and a couple of feet in from the side walls. Once in the correct spot they reward with a very even performance with no frequency area being unduly highlighted. They do have that legendary midrange and just the right amount of top end sparkle. Where they surprised me most was in the bass end. They have weight and clarity that is somewhat unexpected given the size and in my situation excite the room modes less than pretty well any other speaker I have had in my room, that is any speaker with comparable range in the low end. I think the front porting helps in this regard. So, and again agreeing with Phil, I would try them as is and I feel that unless your taste runs to lots of organ recitals or you like to play at rave levels you might find a sub unnecessary.