Control Room Dimensions - What to Do?

My first post here, howdy from Austin. I work out of a studio whose original builder/designer didn't follow some basic guidelines for control room design. The space is a virtual square (20.5x20) with a 10' ceiling. Woof, woof. Given existing structural limitations, the best we could do would be to narrow the room to 17' (giving us 10' high x 20.5' long x 17' wide) but I'm concerned about the 2:1 length to height ratio and what that is doing to accentuate certain modes. The drastic option would be to shrink the CR to 17'x14"x10', thereby losing 42% of our area/volume and changing the whole vibe of the room. We have all the acoustical treatments one might need - bass traps, diffusors, and 703 - and can place them wherever they're needed. Is there any hope for a decent-sounding CR with the fixed 20x10 length and height? Thanks in advance for your thoughts and ideas.

well if you run angled slots down two opposite walls you've fixed the square problem ;) and solved the low mid problem leaving the highs to deal with ;) cheers john

Thanks, John. As I've gotten some more feedback on this topic on other boards and from a few designer friends I'm more confident that we can deal with the room dimensions and come out with a nice sounding space. We have plenty of 703 of different thicknesses to handle the highs plus more RPG and Acoustics First diffusor panels than we can fit on the back wall. As a follow up, would absorptive clouds above the mix position help? I think the ceiling is too low for any kind of diffusion to work there (my partner suggested using some of our spare diffusor panels on the underside of the clouds but I respectfully disagreed...).

Yes - clouds are a cheap and efficient way of treating ceilings. cheers john