The SUBWOOFER PROS Studio Sub 18 is a self-powered high-end subwoofer system employing bass management, hi-pass filtered outputs, and a sealed box front firing 18" high excursion cone low-frequency driver. The use of the INFRA™ technology (developed by Bag End) mated to a built-in 400 Watt US built power amplifier provides flat acoustical response down to 8 hertz. Maximum half space output level at 40Hz from a single Studio Sub 18 is approximately 113dB. Flexible input methods are available including a dedicated LFE input, a six input panel for 5.1 surround programs to either sum all the inputs to a single sub output or to have channel dedicated subwoofers. Five High Pass line level filtered outputs are provided for all 5 surround monitors via built-in bass management. A line level Infra™ output is provided for adding matching "slave" subs for increased SPL output or improved room behavior. A unique Dynamic Filter™ protection system maintains undistorted bass despite the input level, without using compression.