There is no such thing as an Aerial 9B. The Aerial 9 has not changed since it was introduced. I own a pair and they are wonderful sounding dynamic speakers for largish rooms, although not quite as good for small rooms. The downfiring port and front firing drivers are probably a good thing for your stated 2 feet from the wall. While these may work well in the room you describe, IMO the horn options would also work well with the benefit of requiring less amplifier power to drive. Even though the Aerials are rated 90dB at 2.83 Vrms and 1.0 meter on axis, I would not use less than your 400 wpc @ 4 ohms and preferrably higher to really make them come to life in your larger room. If you like the Aerial sound, the 9 will take you toward the direction you are trying to go, but may not be a night and day difference. Aerial also makes a great sub - you could add two of them with either the 7B or 9 for a very dynamic set-up. Although I really enjoy Aerial speakers, IMO, the horn options will provide a more dramatic sonic change in your large room.