BW, the frame(basket)of a driver should be strong enough to hold the active elements in proper position and shouldn't audibly "ring" when attached to the enclosure. If these criteria are satisfied, it doesn't make any difference what the frame is made of or what process was used in manufacturing it. Ian and Andrew have said that the stamped Axiom frames are fine and the die cast version has no audible benefit. There's no good reason, technologically or in practice, to doubt this.

The die cast frame metal is squirted into a form at high temperature and under high pressure. This takes time to form and cool down(as much as 10 minutes each). Stamping gives the metal one bang and that's it; a quicker and less expensive process. Other factors being equal, either process results in entirely satisfactory frames for speaker drivers.

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Enjoy the music, not the equipment.