Paralell CR wall treatments?

I have a control room with a main area of 17x21.5 and 8.5 foot ceilings. I may loose up to 8 inces on the front and right side wall with some new "sound proofing". there is also a bit of extra space at the back of the room as shown in the diagram. The walls are paralell and I am trying to understand if there is some conventional wisdom for treating the side and front walls near the mix postion on a room this size. The walls are currently just painted dry wall and I was considering covering them with thin canvas type fabric or maybe even velvet. Would a more complex diffusion scheme be advisable or just leave it kind of live. I may add a window to the left wall near the mix postion. Any ideas or previous articles any one could point me to? Thanks

Go Here http://www.johnlsayers.com/HR/index1.htm Bryan Giles