Initially I would set them up strictly as stereo pairs, one set Axiom then the Klipsch. Play some music with each set and take notes as to what you are hearing, ie, too much treble, muffled midrange etc. be sure to try varying music styles. Once that is done sit back and read your notes, you might be surprised by what you are hearing between the different speakers. I would then do an A/B comparison as you are suggesting to really hammer home the differences or similarities. One suggestion would to have some else switch between the 2 speakers on the amp without the listener knowing which set is on, this makes it about as blind of a listening test as possible without going through coverings for the speakers etc.
