4642A Dual 460 mm (18 in.) Subwoofer System The JBL Model 4642A is a high quality subwoofer system, featuring an advanced technology 460 mm (18 in), low frequency transducers mounted in a direct radiator, bass-reflex enclosure for smooth response to the lowest audible frequencies. The 4642A is ideal for low-frequency augmentation of either analog or digital soundtracks in motion picture theaters and for general sound reinforcement applications.
Ultra Long Excursion Very High Power Dual 18" Cinema Subwoofer 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").