I thought it might be handy to post the optimal dimensions for listening rooms:

          Design Option    Design Option       Design Option
                    A                      B                          C

Room width =  
           1.14 x Height     1.28 x Height            1.60 x Height

Room length =  
        1.39 x Height       1.54 x Height           2.33 x Height

Length/Width =  
               1.22                       1.20                           1.46

Perhaps these could be pinned to the top of the Room Treatment Forum.

I will follow the dimensions you have mentioned above, because the acoustic depends largely on the refinements of the auditorium dimensions.