HDP4 Hertz 4-Channel 1000W Max D-Class Amplifier HDP4 Hertz 4-Channel 1000W Max D-Class Amplifier RMS Power Output @ 4 ohms: 150 W x 4 RMS Power Output @ 2 ohms: 250 W x 4 THD: 0.08% Dimensions: 6.73 x 11.18 x 1.83