I can't even fathom where to start in my new room ... well I guess I need the gear all in here first! LOL For now I'm likely not going to do very much to the room itself as I've decided not to do the reno's for the new setup yet, I want to wait until I have a bigger budget
That mirror trick is helpful, but it's also good to remember that sound does not work the same way as light does. There's also a ton of other factors to take into consideration -- like the distance from the back wall to the main speakers ... this link has some pretty good info for bass issues (and some stuff waaaaay over my head, see the formulas at the bottom, eeek). It's semi-specific to their monitors, but there's a lot of good general info for problem solving too.
http://www.genelec-ht.com/learning-center/faq/acoustical/bass/I've seen a couple of large rooms mapped out for frequency response, etc .. it's pretty intense. When EAW pitched a new sound system install into one of the large upscale theaters here in toronto they did a full analysis of the room. They charted out the actual response curve at every seat in the theater with their simulations! After they did the install they also went and measured the curve at every seat. Rumor has it they hit their mark
Mark