Pioneer GM-A6704 Bridgeable 4 Channel Amplifier (Black) Why put an amplifier in your car? Pioneer's GM-A6704 4-channel amplifier will greatly improve the sound quality in your vehicle, so you'll find yourself looking forward to your time on the road. This punchy Pioneer will power your front and rear speakers with 60 watts RMS each, which is a large jump over the power supplied by a typical car radio. You'll hear much more of the little details in your music, especially when you turn your system up to overcome road noise. 8-gauge power and ground leads recommended - wiring and hardware not included with amplifier preamp and speaker-level inputs.