I just stumbled on this thread. Great going, Sam! Not many people have the luxury of being able to invest so much space for our hobby!
I don;t know a whole lot about room acoustics, but I think you might have to rethink
both room dimensions:
1) Your theater room is 10 x 15 x 8. I assume that's width x length x height. That would mean the length is exactly double the width. From what I understand, if the length of the room is twice it's width, it will be difficult to tame the room nodes, with bass becoming distorted.
2) Your theater room is 10 x 10 x 8. That would make that room perfectly square. A perfectly square room is considered to be an acoustic nightmare (with perfectly cuboid rooms even worse. Apparently square rooms can be managed somewhat with careful placement (usually placing speakers asymmetrically with a corner behind them), but why start with a compromised room if you have a choice?
If you have the option to, perhaps you could revise the room sizes to 10 x 14 x 8 and 10 x 11 x 8, OR 10 x 16 x 8 and 9 x 10 x 8, depending on movie/music priorities? Or you could just combine the theater and music rooms (not an ideal solution IMHO because of the difference in treatment levels involved) to a more ideal dimension.
I'll be happy to be corrected by FMs if I'm wrong about this.
