Ideal ratio acoustically
 

I'm in the early planning stages of building a dedicated home theater, I never built an attached garage since I have a huge shop in the back yard so I have a spot that's approx 33' long & 20" wide to add a theater on to my house.

The question is acoustically speaking is there an Ideal ratio for width, Hight & length for the room?
With a 30' length what should my other dimensions be inside the room to get the best acoustics?

Re: Ideal ratio acoustically
 

1.14 times the room's height for width.
1.39 times the room's hieght for length.

or

1.28 Xh=w
1.54 xh=L

or

1.6 XH=W
2.33 XH=L

There is also the basic rule that one dimension can't be evenly divided by the other. You should add a 12'6" ceiling and you should be just about perfect according to the 3rd option for optimal sound.

Re: Ideal ratio acoustically
 

In case you're wondering those are numbers considered ideal by Louden and Sepmeyer. Designers refer to them as the Golden Ratios.