OSD Audio's SMP1000DSP Class D Digital Subwoofer Amplifier is a 1000W (4 ohms) amp designed to power passive subwoofers used in home theaters or media rooms. Measuring less than 20 inches wide and 10 inches deep, packed inside this compact profile is the latest in high-efficiency digital amplifier technology. The SMP1000DSP is a Class D digital amplifier that combines the best qualities of both Class A and B amp protocols into a highly efficient compact chassis, while Digital Signal provides superior control of low-frequency effects. This sleek, low-profile sub amp uses highly efficient Class D circuitry with the latest Digital Sound Processing so your subwoofer receives that kind of current that makes the difference between decent bass and “I can feel it in my chest.” Class D amplifier technology combines the best qualities of both Class A and B amp protocols into a highly efficient and compact digital design that is ideal for budget-minded users who want a feature-rich digital sub amp that does not run hot or take up a lot of space. Class D amplifiers use output transistors that are fully turned on or off during operation so distortion is low, efficiency is high (93%) and Class D amps run cooler than their Class A/B cousins. It also includes Digital Signal Processing for superior control of low-frequency accuracy. This robust sub amp also includes an adjustable low pass crossover (35Hz – 180Hz) to manage the overlap of the subwoofer's upper frequencies and the main speakers' lower frequencies for balanced and seamless sound. With both RCA and speaker level connections, the SMP1000DSP will be compatible with both old school and modern source equipment, and it includes RCA line out to another amplifier should you decide to expand the bass down the road.