"Small" is not the real story here. Making an amplifier small is great, of course... but not if power and sound quality are sacrificed. This is why our engineering team focused on achieving world-class fidelity first, and then on making our HD amplifiers amazingly powerful, efficient and small. These efforts led to a remarkable switching amplifier technology called Single Cycle ControlTM, which allows all of these goals to be achieved. This exclusive core amplifier technology is mated to our regulated, intelligent power supply (R.I.P.S.), advanced thermal management systems and a full complement of studio-grade processing features to put the all-new HD amplifiers in a performance class all their own. We invite you to sonically compare the HD amplifiers to any amplifier, at any price... We think you will quickly discover that all the old amplifier compromises have suddenly vanished. Patented Single Cycle Control switching technology corrects output in each and every switching cycle (over 400,000 times per second) for pristine power delivery. Studio-Grade Signal Processing. A full complement of expertly executed signal processing features make HD's flexible in application and a joy to tune in a variety of system designs. Advanced Rollback Protection and RealSink. Real, cast aluminum finned heat sinks and our "never-quit" rollback circuitry eliminate annoying thermal shutdown events. Remote Level Control (HD-RLC). With the addition of an HD-RLC you can control the overall level of the amplifier (or amplifiers) from the front of your vehicle. R.I.P.S. System. The remarkable R.I.P.S. System ensures consistent power delivery over a wide range of battery voltages and load impedances. Differential-Balanced Inputs Greatly reduce noise and provide compatibility with a wide range of sources, including most OEM systems. HD Amplifiers have two mounting options to ease in installation and can also be stacked with an optional stacking kit.