The A120 is a Class D 120 Watts amplifier thats got all the muscle you need to drive even the most demanding subwoofers to house-thumping levels, and run cool under almost any load. The A120 features a stereo/mono line level audio input that can receive full band line level audio from an audio amplifier, receiver, preamp or LFE output on just about any appropriately featured device. The adjustable crossover allows fine-tuning the A120 low frequency input setting to properly complement any full-range speakers or room conditions. In addition, the A120 features a phase adjustment that provides sub performance optimization given the sub's placement relative to the main speakers. The A120 also features a stereo speaker level input. Amplified stereo audio passes through the A120 full-band and unprocessed to a pair of connected stereo speakers. The speaker level input is also processed by the A120 crossover, phase and volume controls to enhance and optimize low frequency content. This feature is an easy way to add amplified in-wall or in-ceiling subwoofers to multi-room audio amplifiers that do not have zone-specific line level outputs. The A120 is audio-sensing so anytime an audio signal hits the A120 inputs, the amp will instantly turn ON. The amp will turn itself OFF after 15 minutes when no audio signal is present. There is also a 12VDC Trigger input that will turn the A120 ON when 12-24VDC is applied and turn the amp OFF when the voltage is removed. The A120 is the perfect match for many applications but makes a particularly great running mate with the Beale Street Audio D2.1 Stereo amp with subwoofer out.