Well, last night I re-did the cable connections and also checked the screws on the center woofers and tweeters. For every driver there was at least one screw that could stand to be tightened. However on one of the tweeters two of the screws would not tighten down at all no matter how much you turned them, apparently the threads are stripped which concerns me somewhat.

By the time I did all this my wife was in bed so I didn't get to re-check for the sound issues. I'll do some more listening tomorrow and if the problem persists I'll contact Axiom to see what we can do.