Cadence Acoustics Xa400.1 850 Watt Peak Mono Block Class D Amplifier (Orange) Cadence Xa400.1 class D mono block amplifier 300W @ 4 ohm RMS, 425W @ 2 ohm RMS, 850W Xenith Power Frequency Response: 10Hz - 250Hz Minimum THD: 97dB, Damping Factor: &gt;160 @ 100Hz Dimension (L x W x H): 12.8 x 10.5 x 2.6 inches