JBL Stage A120P Active Sub Woofer

Jbl Stage A120P 12' inches Powered Subwoofer.
frequency response: 32-150 Hz
250-watt RMS amplifier (500 watts peak power)
12" polycellulose woofer
bass-reflex design with rear-firing tuned ports rear-mounted volume, crossover, phase, and power controls
continuously variable low-pass 50-150 Hz crossover
phase switch to acoustically match the subwoofer's output to your main speakers
main power on/off switch plus auto standby/on mode.