for a given coil movement, cartridge output is simply the combination of flux and length of wire in that flux. In order to change one you must change the other to get the same output. The third side of this "triangle" is the cartridge impedance which shows up in the form of mass. In order to reduce the mass of the coils you can either use fewer turns (less length of wire = less output) or the same number of turns of a thinner wire which increases impedance. There is a current trend of trying to drive the turns and impedance down and still maintain a substantial output which is where the strength of the N52 neo magnets come into the picture.
dave
dave