Infinity's Reference Series amplifiers offer impressive power and extensive controls for fine-tuning your sound - an ideal way to boost your music's intensity and clarity. Strict reliability testing results in durable, dependable amplifiers, and their compact size gives you more installation options in tight places. The heavy-hitting Infinity Reference 475a 4-channel amplifier sends 75 watts RMS to each of your front and rear speakers. Or, you can bridge the amp to 2-channel mode, and pump out 360 watts total to your two subs. And every Infinity Reference amplifier is certified to deliver power as advertised. The variable frequency filters and adjustable bass boost let you contour the amp's output to suit your speakers or subs for more efficient output and cleaner low-end kick. Preamp outputs simplify hookup to another amp in your system, so system building is quick and easy. Direct-connect terminals make reliable connections without need for any crimping or soldering.