W3v3 Subwoofer Drivers (from JL Audio's web site)

Clearly the best sounding W3's yet, these subwoofers feature DMA-optimized, 
long linear excursion capability to minimize distortion and increase output. 
W3v3's are available in single 2 ohm, 4 ohm and 8 ohm versions (6W3v3 available 
in 4 ohm and 8 ohm only) and are superb performers at medium power levels in 
compact sealed or ported enclosures.
 
Multiple patented technologies enhance performance and reliability. As with 
JL Audio's flagship drivers, development was guided by JL Audio's proprietary 
DMA (Dynamic Motor Analysis) modeling system to deliver outstanding dynamic 
stability and low-distortion operation within their intended power envelope.

A mineral-filled polypropylene upper cone body with a metallic JL Audio logo 
medallion provides a classy new look, while a removable (and customizable) 
mounting flange trim ring receives grille-mesh inserts directly, without the 
need for additional grille hardware. (Grille mesh inserts are sold separately.)