Pioneer GM-D1004 Compact 4-channel Car AmplifierDouble the power, double the fun Pioneer's GM D1004 4 channel amplifier will power your front and rear speakers with 45 watts RMS each that's almost three times the power of a typical factory radio or aftermarket receiver. Even better, this compact amplifier runs so efficiently that it can often get its power from the same circuit as your receiver, saving you some wiring hassles. And its tiny size means you can install it almost anywhere, even behind