The JBL 18-inch Passive Subwoofer System can be easily used by musicians on tour as well as by audiophiles in their own homes. It’s capable of blasting sound through an amphitheater or a movie theater. This subwoofer provides a maximum of 141 dB SPL output in the 30-150 Hz frequency range with a 47-120 Hz frequency response. You’ll be able to feel this subwoofer’s beat through the floor, through the walls, and through the air.