Easy. 64 feet by 70 feet by 50 feet high.
OK Ethan and friends. I want to build a great studio for grand piano and choral recording. Let's say that I am building from scratch, in a shell. What dimensions would you use and why?
When you die, you can't take it with you. So, can I have it?
Come on, the guy's name is "low D". If he builds a room with those ratios (70x64x50), he'll wind up with modal resonances at low Bb, low C and low E, and the resulting whole tone scale could send him into lala land and cause him to have an identity crisis.
Hey Brent, what's the lowdown on your budget? How many square feet can you afford?
Wes Lachot Design
Actually, it is possible to talk about room ratios without specifying square footage or volume, since the whole thing can be shrunk or expanded without affecting the relative dimensions. It's just hard to know what's practical without more specific info.
The various books by F. Alton Everest list several sets of ratios relentlessly, and there is a danger of folks blindly believing that these are the only possible "good" ratios. In truth, the possibilities are somewhat limited, but there are plenty more good ones than the ones listed.
In one of his books, Everest mentions this set of preferred ratios:
1 / cube root of 2 / cube root of 4
This looks a little scary at first, until you realize that it's really just a series of major thirds, like C / E / G#.
Those would be the fundamentals, then you'd have 2nd harmonics an octave up, again at C,E, and G#.
It doesn't take a musical or acoustical genius to figure out that we're looking at very even modal spacing in the first 2 octaves, and that's where modes really matter. How could it be any more even?
So there you go. But there are others, so don't give up if these aren't practical.
Oh yeah, I almost forgot. Translating to feet and inches, that would be 16'-0 H x 20'-2" W x 25'-4 3/4" L. You can make the whole thing larger or smaller by multiplying all three numbers by a common factor.