Although i disagree with JohnK on the first point, i agree with him on the second point.
Adequate amplification is indeed a strong consideration when powering speakers, especially with those rated at 4 ohm and Sony has never been known for its beefy amp sections. Yes, even at low to moderate SPL this will make a distinct audible difference.
However, one must guard against the expectations our brain may set when buying a new pair of speakers. The concept of "blown away" or "night and day" sound is so over exaggerated by many who report such findings that new buyers are less than overwhelmed by the general lack of amazement upon receiving and hearing their new units. It is called "bias" and everyone has it, everyone does it, consciously or not.
Give the speakers a couple of days and try listening to some different recordings. Borrow a different and capable receiver from a friend or family member, or get one from a store on a returnable basis to use as a comparison. If in the end you still feel they are not worth the cost or change, then send them back.
That is the beauty of the Axiom sales philosophy, 30 days return full refund (except return shipping).
