When you say the M2i has an Aluminum Woofer, does this mean it has an Aluminum cone or is the actual structure Aluminum?

Aluminum cone.


If it were an aluminum frame it would read something like:

Cast aluminum basket or around there.

Yeap, the actual cone is aluminum; it is done so that it is lightweight and moves more freely (less inertia). A well done Aluminum cone can have the same benefits as implementing a phase plug (but without the added dust factor), and without the added ventilation (even though the cone acts as somewhat of a heatsink, it doesn't have too much of an effect.) The heat dissipation abilities of the aluminum cone I would belive are akin to that of an aluminum computer case (marginally better, but nothing to write home about). Although I must say, the metal cones are extremely cold to the touch when not in use (and they seem to get a bit warmer when in use, which is a good thing.)

But the fact remains that it makes the cone considerably lighter, which will improve your mid-bass accuracy.

In addition to the lower mass, another major benefit of the aluminum-based cone is its higher rigidity, i.e., higher internal velocity of sound propagation. This means that the cone moves uniformly (without "breaking up") over a wider frequency range. A potential drawback of the aluminum cone its low intrinsic acoustic loss, or high Q around the upper-end resonance frequencies. They usually need some kind of laminated aluminum materials to "dump" the resonance (I don't know what exact treatments the Axiom cones receive).

I believe that heatsinking ability of the aluminum cone becomes fairly significant when the speaker is driven at high average power levels.