The Action 18A is a powered subwoofer system designed to provide extended bass response for the Action full-range cabinets. A 1500W peak Class D amplifier drives a D.A.S. 18H bass loudspeaker. The 18H loudspeaker incorporates a 4? voice coil for high power handling and output. The subwoofer system includes two balanced inputs with stereo filtered output connections for Action satellite systems. The variable crossover ranges from 100 to 160Hz and can be defeated to offer stereo loop thru connections. A gain control and polarity reverse feature increase user control over the system.