Tinkering with the cross-over in the M3 does not seem to me to be a worthwhile use of your time, even for just to see what would happen. It is hard for people to believe Axiom owners commenting in an Axiom forum that the perceived brightness is not a function of these speakers but rather a function mostly of the original source media. There is no denial, cover up, ignorance, or high-frequency hearing loss with regard to owners who make this claim . Remember that most commercial CDs are tweaked with EQ and compression, and Axioms tend to reveal this because of their brutal honesty. I have heard imperfections and vast differences in quality of recordings with the Axioms. Some recordings sound shrill and some so life-like as to send chills through my spine. I like this revealing honesty about my Axioms and would not dare to tinker and corrupt their personality.
John
