The original Magnums were modified Grado 325 drivers liberated and housed in a metal (not plastic) inner cup. The also featured metal gimbals with slightly thicker rods (more friction in rod blocks) to compensate for the heavier weight vs. stock 325.
ORIGINAL MAGNUM HEADPHONES = MODIFIED 325
The current Magnum are not modified Grado drivers and have little relation to the original Magnum product in that they are only selling drivers and not modifying headphones. As such the final product will vary based on the various components and methods (cups, cables, housings, mounting technique etc) used to make the final headphones.
CURRENT MAGNUM DRIVERS