Well i have this question and i reakon its one of my better ones.

Pro audio speakers ~ What coil design allows the big woofers to play up higher compared to whats considered a normal speaker of the same size.

Lower inductance, MUCH better power dissipation, smaller coils diameters, smaller gaps, larger BL for a starter.

Its not just the motor though. Pro drivers have softer spiders, and much better roll surrounds to allow playback through the breakup node. Traditionally, they also had a flatter cone profile. Thats why Pro Audio units need larger boxes. Car Audio is actually the compromise field. The push for smaller boxes, lower impedance and poor power handling (across a large frequency range) to allow units that work well in a 'drop-in' situation.

Keep in mind, a Pro Audio speaker isnt designed primarily for audio accuracy and quality. They are designed to be thrashed seriously hardcore, for hours and hours at a time.