The Axiom board deserves a gold star JohnK. What is interesting to note is not the stated 4 ohm nominal rating but where in the frequency range the impedance dips are occurring. This explains why 8 ohm rated speakers like the M22 that dip down to 3 ohms (the version based on the soundstage measurements) never caused A/VR's to go into protect mode because the dip is occurring higher in the frequency range at 4k. Even though the M60, M80 and VP180 which have slightly higher minimum impedance dips but where they are occurring is in the 50hz and below range which will cause much greater demands on the AVR at reference levels.
