SUNDOWN AUDIO SFB-1000.4D | 4 CHANNEL CLASS D AMPLIFIER FEATURES & SPECIFICATIONS: Number Of Channels: 4 RMS Power @ 14.4V DC - 1 Ohm 1050W x 4 Channels RMS Power @ 14.4V DC - 2 Ohm 590W x 4 Channels RMS Power @ 14.4V DC - 4 Ohm 350W x 4 Channels Input Sensitivity: 200MV Signal To Noise Ratio: 100dB Frequency Response: 10HZ-20KHZ(-3dB) Input Impedance: 56k ohms Proctection System: Output ShortHighLow Supply VoltageThermal Protection Minimum Supply Voltage: 9VDC Maximum Supply Voltage: 16VDC Crossover: H.P.F: 15Hz to 6KHz Variable L.P.F: 50Hz to 6KHz Variable Bass Boost: 0 to 12dB(50Hz) Smart Cooler (fan powered by temperature or audio)