BANDA ELITE 4000.4 One Channel 4000.4 Watts Max @ 1 Ohm Car Audio Amplifier. Do not use impedance load lower than the amplifier specification. This can damage the equipment. Use wire solder for tinning the cable end for better electrical contact. Loose electrical connection can cause malfunction, heating and even fire. The GND connection must be as short as possible, using an adequate wire terminal firmly connected to a clean, paint free spot at the car chassis. It allows you to adjust the Crossover by selector key: LOW, FLAT e HIGH. This function, when LOW is selected, allows the device to adjust only the low frequencies (20Hz - 90Hz @ -3dBs). FLAT position is FULL RANGE mode (20Hz - 20kHz @ -3dBs). HIGH position allows the device to adjust only the high frequencies (90Hz - 20kHz @ -3dBs).