First, welcome to the splendor of the Garden State! Things must be real bad in the UK. Heh heh. Anyway, try hanging a blanket over your TV. All the reflections bouncing off that can mess with your imaging. Been there. Also, if you haven't already, take the grills off the speakers. These are two easy freebies that could help.
Also agree with Jond that in that room wide dispersion speakers (i.e. Joseph Audio) might be problematic. Something like Vandersteen might work better and also improve imaging. If you can make it to Audio Connection in NJ I'd highly recommend going.
All that said, if it's me and given your room I'd first absolutely try a room correction device like DSpeaker as amp1231 suggested. There are very few rooms that don't DRAMATICALLY benefit from room/speaker correction, and in your case it could potentially solve a multitude of problems. I've heard several of these at shows and in personal systems, and after hearing the corrected result you just wouldn't even want to listen to the non-corrected version -- it literally sounds broken by comparison. Buy used or try some kind of demo, but definitely explore this path. It could well save you tons of time and $$$ playing with room treatments and equipment. Best of luck.
Also agree with Jond that in that room wide dispersion speakers (i.e. Joseph Audio) might be problematic. Something like Vandersteen might work better and also improve imaging. If you can make it to Audio Connection in NJ I'd highly recommend going.
All that said, if it's me and given your room I'd first absolutely try a room correction device like DSpeaker as amp1231 suggested. There are very few rooms that don't DRAMATICALLY benefit from room/speaker correction, and in your case it could potentially solve a multitude of problems. I've heard several of these at shows and in personal systems, and after hearing the corrected result you just wouldn't even want to listen to the non-corrected version -- it literally sounds broken by comparison. Buy used or try some kind of demo, but definitely explore this path. It could well save you tons of time and $$$ playing with room treatments and equipment. Best of luck.