all the sound systems for the general audience have rear speakers. we normally use a 6 channel amp for the fronts and a seperate sub amp. when we build competition systems, there is no rear stage. the rear speakers should not be audible from the front, but you would notice if they were gone. thats how i set up the sound stage. just fading to the front without time alignment wont be a good comparison to how it would sound after you add the processor