What kind of speaker wires are used internally on the M2ti? I assume it is copper, but what material is the insulation, and has any effort been made to seal and prevent the wiring from oxidation?

It sounds like you believe the wire is bare copper strands?

While I have not disassembled a new pair of Axioms, the AX3's I have are wired with Sound King. The subwoofer is wired with 12gauge, and the mid and tweeter are lesser gauge. I had planned to upgrade the wiring before I realized it was of sufficient size and quality.

Do you have specific concerns in this area?

Oxidation was my only real concern. Other than that, changing the internal wiring would be a potential tweak sometime in the future, but not very likely.