Optimum size for music room?

There is a relationship called the Fibonacci Series. Cardas says it is to be found everywhere in nature including the nautilus (snail?) they use in their logo.
Essentially it provides the relationship between length, width and height which provides the least reverberation and cancellation.
I imagine there are other people on this forum who can explain it better than I can but I believe I calculated something like
22 x 13 x 8 once upon a time.
Draw a line about a foot long running from left to right. On the left end write "A" and on the right side write "C". Then you figure where to place "B" along the line by locating the point where BC is to AB as AB is to AC. In other words, find the location where the shorter segment is to the longer segment is the same as the longer segment is to the whole line.
As it was explained to me, this will be the ideal dimensional ratio to employ in designing your room.
However, I like the idea of non-parallel walls too, and I cannot imagine how that gels with what I just proffered.
Good luck. This doesn't seem like a good place to proceed by trial and error.

I have imagined a suspended floor with individual concrete piers under the speaker areas and the equipment rack. You need to make them large enough to be able to move gear around on them especially for speaker placement. This arrangement would eliminate mechanical feedback completely, I think, but you still have the earthquake threat in your neighborhood.

I've also noticed that listening rooms often have low ceilings and concert halls never do. Tiger's room mentioned above seems to have been an inspired design.

The concert hall at my local college has the stage at the narrow end and the ceiling over the stage is at the lowest point in it's arc. In fact, the way the walls fan out and the floor and ceiling rise as they move away from the stage, seems to mimic a horn to a certain extent.

The question is: how much of this design was created to optimize acoustics and how much was put in place to maximize seating area? Anybody know?

The acoustics in there are very good and there are room treatments built in to the decor.