An easy fix is to turn the gain knob on the sub down to 1/3 or 1/2 of max as per Axiom sub setup manual, rerun Audyssey, and then turn up the gain on the sub a bit to get to a desired level.

This is not the most scientific method but if you like to run your sub a little hot, no harm done.

"If you try to turn toward it, you go against it."