Dave the room , the gear, ect. are not neccessary to rate one speaker against another as he is keeping his same set-up.
any room can be made accoustically correct, my room is a perfect example. This guy is talking about switching speakers not his amp, entire set-up. So the sound from a new speaker is going to sound different wheter it be b&w, Wilsons, Focal, CA audio, ect.
What he wants to know is if the D series is superior to the N. The simple answer is yes by about 50%. B&w does not come out w/new models every year like most speaker manufactures to try to boost sales. The Natilus ran for 7 years. B&W only makes changes to their design when they can honestly improve it, not just change colors of box design, their philosy is form follows function, hence the lack of noticable difference in apperance between the N & D. Much like Porshe. If y start w/a superior design their is no reason for a complete overhaul.
Kodg.
