I haven't been on for a long time, I didn't really have much to add...until now. Axiom's new speakers with the rear facing drivers (the 1100's) will be quite the upgrade. I, however...could not wait to try them. Sooooo, I just got (from a new hybrid speaker mfg) my new "Backfire bolt-on" rear driver set. These blow away any speaker without them! They are on the web at: www.Backfirebolton.com
They are easy to mount...you just drill 10 holes on top of your mains, and connect them to the crossover with the provided connectors. I will add a picture of my set mounted to my M60s for all to see...plus, they perfectly match the original factory finish of your mains. Thanks, and check them out!