MTX Audio TS9924-22 Jackhammer Super Subwoofer 4,000 RMS, 8,000 peak music power 23" tall 400 lbs. 900 ounce strontium ferrite magnet with extended magnetic field gap technology 6.5" voice coil with 17 AWG high temperature aluminum wire in a flat wound, long-excursion design incorporating 2.5" of Xmax