JBL GX-A604 435W 4-Channel GX Series Amplifier GX Series 4-Channel Car Amplifier RMS Power Rating: 4 ohms: 60 watts x 4 chan. / 2 ohms: 85 watts x 4 chan. / Bridged: 4 ohms: 170 watts x 2 chan. Max power output: 435 watts Variable Bass Boost (0 to +12 dB bass boost at 45 Hz) 4, 3 or 2 channel operation