OSD Audio SMP300 Class D Digital Subwoofer Amplifier Rated at 300W Max

"If you're ready to beef up the bass in your surround sound system, OSD Audio's SMP300 is a Class D digital mono subwoofer delivers up to 300W of peak power to passive subwoofers so you can enjoy three dimensional surround sound from movie and music soundtracks. 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 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.

Variable Low Pass Filter and Phase
OSD Audio's sub amp includes a front-panel variable low pass filter that allows you to adjust the upper frequency limit of the subwoofer to control the overlap of the subwoofer's upper frequencies and the main speakers' lower frequencies. This results in bass that complements the sound from the main speakers rather than overpowers. A front-panel variable phase control knob operates over a range from 0 degrees to 180 degrees and allows you to match the arrival times of the sound waves from the subwoofer and the main speakers. This fine-tuning results in bass that is less muddy or thumpy but rather smooth and detailed.

Includes Class D Amp Technology
The SMP300 uses Class D digital amplifier technology that combines the best qualities of both Class A and B amp protocols into a highly efficient compact chassis 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. "