PBM sealed enclosure subwoofer creates an impressively solid bass foundation for your music and movie special effects. It employs a custom built 12 inch long throw driver with a treated cellulose composite cone. The massive, magnetically shielded and vented motor structure in itself weighs over 5 lbs! Power is supplied by a 150 watt discrete Class G amplifier specifically matched to this driver. Auto signal sensing turn on, an adjustable crossover, Absolute Phase switch, and front mounted variable level control complete this fine woofer¹s feature set.