Boss S12A 12" 1200W 4-Ohm Amplified Subwoofer Enclosure Subwoofer Size: 12"" Subwoofer Type: Amplified Total Power Output: 1200 Watts RMS Power: 600 Watts @ 4 Ohms THD 0.01% Built-in MOSFET Power Amplifier Bass Boost Selectable 0 / +18dB Sensitivity: 92dB Low Pass Crossover Range 40-160Hz Signal-to-Noise Ratio &gt;103dB Impedance: 4 OHMS 12"" Subwoofer Subwoofer Frequency Response: 20-200Hz Amplifier Section Frequency Response: 40-200Hz The Enclosures Are Custom Designed And Tuned To The Subwoofers They House. The Built-In Amplifier Is A Perfect Match Driving The Subwoofers To Their Maximum Without Distortion And With Plenty Of Headroom. Built-in MOSFET power amplifier; 12-inch subwoofer Frequency response: 40-200Hz; Impedance: 4 ohms; Sensitivity: 92dB RMS power: 600 watts; Max power: 1200 watts