OSD Audio's SMP300 is a Class D digital mono subwoofer that delivers up to 500W of peak power to beef up the bass in your home theater or audio sound system. Designed for use with passive subwoofers such as in-wall subs that require external power, the SMP300 provides continuous, stable power but measures only 3' high so it can fit inside any equipment rack or cabinet. Moderately priced with high-end features, this compact sub amp enhances the low frequency sound effects on music and movie soundtracks so you’ll experience highly accurate bass and a more intense surround sound experience. The SMP300 includes variable low pass filter control for balanced and seamless sound quality as well as variable phase control for additional fine tuning. Multiple connection options include LFE input, line-level and speaker-level inputs to cover newer and old school source equipment.