<p>Class-D amplifiers overcome the inefficiencies of traditional Class-A or AB amplifiers. Pioneer&rsquo;s Class-D amps transform very little power into heat so a higher percentage of the power supply (67%) is transformed into the load. This results in a very compact amp which needs less input power to produce very high output power. The Class-D amplifier&rsquo;s PWM (Pulse Width Modulator) modulates the original audio input signal with a triangulated signal wave which has a much higher fixed frequency. The result is a digital signal which contains both the input signal and a band of frequency components around the modulation frequency. A LPF (Low Pass Filter) then filters out the high frequency pulses and the resulting amplified output signal is then sent to the subwoofer and/or speakers.</p>