I have both the 140's and 1Sc's, which I use in the same room, alternatively. Room is 12 x 13. In my room, the base on the 140's is better then the 1Sc's. Mid range on the 1sc's is better then the 140's. I also have a center channel 140. I had heard the D15 at a dealer but felt the 140's better. I have tried to get the dealer to loan me the D15's so I could see how they performed in my room, but no go. Brought the 140's elsewhere. The room has no bare walls, mostly book shelf's, large double windows and open racks. Still tweaking the room. All amps, four monoblocks and one inter, are tubes. I have also run the speakers from ss monoblocks, tubes sound better. I still have the ProAc original tablette and EBT's, the 1sc's are much better.