First, I'm currious as to "why you would want to run the powered mains as small and the rears as full range?" If anything, you should(assuming the mains are a full range speaker with powered woofers) run the mains as "large" and the rears(passive full range towers) as small! The powered toweres do a much much better job of handling "full range" than the passive rears!!! Unless the rears are ULTRA HIGH SENSITIVITY AND EFFICIENCY, this is definitely NOT AS DESIREABLE!(POWERED SUBS DO BETTER HANDLING DD/DTS BASS!).
BTW, how low do the AR1's play and how big are the bass drivers?...this makes a difference in how you might consider crossing them over, if at all.
Worse case scanario, I would run all the speakers as "small" and add a powered sub(s). You could to "full range" to all the speakers if the mains are large enough with big powered woofers. Normally, there's not so much bass info at the rears to sweat it that much if push comes to shove(although not ideal in my experience). Then again you could consider changing your reciever(which is always going to have less current capability to do proper justice to MOST ANY SPEAKER FULL RANGE FOR DD/DTS!(except powered speakers, or running "small + sub"). The possible exception is when you're running speakers that have very very high sensitivity ratings, like 96db+!
BTW, how low do the AR1's play and how big are the bass drivers?...this makes a difference in how you might consider crossing them over, if at all.
Worse case scanario, I would run all the speakers as "small" and add a powered sub(s). You could to "full range" to all the speakers if the mains are large enough with big powered woofers. Normally, there's not so much bass info at the rears to sweat it that much if push comes to shove(although not ideal in my experience). Then again you could consider changing your reciever(which is always going to have less current capability to do proper justice to MOST ANY SPEAKER FULL RANGE FOR DD/DTS!(except powered speakers, or running "small + sub"). The possible exception is when you're running speakers that have very very high sensitivity ratings, like 96db+!