FBT X-Sub 18SA, Active Subwoofer, A very compact 18"" bandpass subwoofer, 1200 watt class D power amplifier, DSP with 4 presets, Frequency response: 38-120 Hz, Stereo input, Link output, HP output, Phase switch: 180°, M20 stand flange mount, Dimensions (W x H x D): 510 x 692 x 650 mm, Weight: 34 kg