SOUND STORM 400W 4 Channels Amplifier Features: Variable input gain control Power and protection LED indicators Line and speaker level inputs Damping factor 125+ Type: Amplifiers RMS Power: 50W x 4 @ 4 ohm Frequency Response: 12Hz - 22KHz THD: 0.01% SNR: 90 dB Built-in Crossover: Yes Crossover Frequency Range: Low pass crossover on CH3/4: 120Hz (fixed)