Fusion MS-AB206 Active Subwoofer with Built-In 4 Channel Amplifier 4 channel Class-D amplifier that delivers efficient and high output Rated Amplifier Power 26 Watts RMS per channel @ 4 Ohms, 43 Watts RMS per channel @ 2 Ohms Frequency Response 25 Hz - 200 Hz Peak Power 350 Watts Total (210 Watts + 140 Watts Speaker Output) Woofer Size 6" Down Firing + 6" Passive Radiator