Pioneer GM-A6604 Compact 4 Channel Car Amplifier Brand: Pioneer Features: Bass boost 8-gauge power and ground leads recommended Switchable high- and low-pass filters Series: GM Type: Amplifiers Amplifier Class: Class AB RMS Power: 60 watts RMS x 4 at 4 ohms 180 watts RMS x 2 in bridged mode Frequency Response: 70 kHz