What would sound better one pair of Infinity kappas 6 1/2 up front with my RF 12' sub or 2 pairs ? I heard somewhere that just putting one pair of 6 1/2 upfront gets better sound imaging then 2 pairs when you have a sub.
You will typically get better imaging from a single set of comps, because you have fewer phase anamolies that will throw an image out of whack. It's the same thing as if you were to put a tweeter far away from the mid, you'll likely have a layered sound because the wave seems to emanate from two different point sources.