Boston Acoustics GT-42 4-Channel Car Amplifier 700 Watts RMS 4-channel car amplifier Q-Tune&trade; technology combines sophisticated crossover adjustments with Q-Control settings to seamlessly transition rear bass to the front sound stage The GT's DPS&trade; (Dynamic Power System&trade;) ensures high efficiency and ouput stages, increased power with lower impedance and maximum dynamics and transient response High-current, high-power design 2-ohm mono operation on all models