Construction Question

I'm taking part of my second story 16' by 24',and raising the walls to make a theater.My question is.I've heard square or rectangle walls are bad for sound.My layout and construction are wide open.Does anyone know where a person could get some info or plans on the net?
If you live in any reasonably large meto area, seek out an HT install/desin center. They will help.

If not, or in addition too, seek out such design reccomendations on the web.

Short answer, if you are planning such extensive construction, you may as well do it right and once!

Check out Rives Audio
Level floor, sloping ceiling(low in front,higher in back), sidewalls not parallel(closer together in front, wider apart in rear). You will need a good framer and drywall crew to accomplish this. Found this after web search:
Rectangular room, coffer'd ceiling, tiered platform seating, Russ Herschelmann's proposed seating and speaker location plan (See old "Home Theater Architect" articles on seating and speaker placement, as well as acoustic treatment), some processor with newer Audyssey DSP room correction tech and multi-channel amplification, PMI "Cine-pannels" around the room, A Klipsch THX speaker system (for passive speakers, you'll not get better for movie playback - within reason), comfortable medium-backed seating, -and you're done.
Er, you might wanna add a projection system and high def sources. My bad...