Does anyone know what using 2 different sized ports would do to a cab? I can think of 2 possibilities. 1) Cab would be tuned to the total area of the ports. 2) Cab would be blurred in its tuning and the ports would unload the speakers at different frequencies. I haven't found any sources to research this topic. It seems that all cabs are tuned with 1 or more ports of the same size. Obviously that would be the easiest way to calculate the results but I wonder if there is more to it than that.