I can see that if the M80's roll off at 30hz and the sub will start to take over ( so to speak ) around 80hz and keep to volumn level going to say 25hz when it starts to roll itself off. OK, I guess I answered the question in the question and calibrated right, would be awesome. But, then if I have a good sub like that why the 80's whynot get a speaker like the 60's where that much bass in a front is not needed that much specially if the LFE is set to 80hz.

You can also contact Axiom and get resistors to put in before the tweeters that will attenuate the highs a bit.