FBT X-SUB 118SA 1200W Processed Compact Bass Reflex Active Subwoofer - 18"The FBT X SUB 118SA , 1 x 18" bass reflex design subwoofer, is the perfect low frequency extension and the ideal companion for the FBT X LITE and FBT X PRO series. The FBT X SUB 118SA provides the following performance criteria: frequency response of 38Hz to 120Hz @ 6dB, maximum SPL of 136 dB peak, 1200W Class D amplifier. The FBT X SUB 118SA provides a DSP processor with 4 presets (2 responses with 2 different cut off frequencies). The FBT X SUB