This 18" powered subwoofer will provide plenty of boom without to shake the room. It gives you balanced in and out XLR jacks, as well as a thru full range output, gain control, LED indicators, a phase switch for switching polarity and a protect mode that will prevent the subwoofer from getting too hot by stopping all output.

18" powered subwoofer
Limit Indicator lets you know when built-in limiter is active
Signal Indicator glows when when there a signal is received to the Full Range input
Subwoofer gain control knob regulates the output level of the subwoofer, and set balance between the speakers and subwoofers.
Protect Indicator glows when the subwoofer goes into protect mode which prevents the subwoofer amplifiers from getting too hot and stops all output
Power LED indicates power is on
Phase switch for reversing polarity of subwoofer
Full range XLR input
High Pass XLR output
Thru full range output
Dimensions: 35.4" x 28.7" x 29.1"
Weight: 187.3 lbs.
Environmental conditions: Operational temperature: 5° to 35°C (41° to 95°F) Operational humidity: 25 to 85% RH (non-condensation)
Storage temperature: -20° to 60°C (4° to 140°F)
Frequency response: (-3db): 35Hz ~ 120Hz
Frequency range: (-10db): 25Hz ~ 120Hz
Maximum SPL at 1m: 128db
Peak output at 1m: 134db
Crossover frequency: 120Hz (12db/octave)
Input type: balanced differential
Input impedence: 50k
Input protection: Level protected
Thermal protection: Input stage muting, auto-reset
Low-Frequency transducer diameter: 18"
Voice coil diameter: 4.0"
Low-Frequency power amplifier: Rated Power* 800 Watts Continuous, 1000W Peak
Rated THD: < 0.03%
Cooling: Passive-Heatsink with speed sensitive electric fan