The 5628 is a high power, lightweight front-loaded vented subwoofer enclosure housing two of JBL’s exclusive 2269H Ultra Long Excursion 18" Differential Drive® woofers. This woofer features neodymium magnet, dual voice coils and dual gaps, JBL’s exclusive Vented Gap Cooling™ and ultra robust composite cone for high excursion and extra long life. Woofer is capable of a peakto- peak maximum excursion of 89 mm (3.5").