Passive radiator powered subwoofer system. RCA & speaker level input. Variable cut-off frequency (50-120Hz). Active subwoofer system with Passive radiator. Dual Voice Coil System. Phase inverter 0°(Normal) / 180°(Reverse). 1 RCA, 1 mini-jack. Die-Cast Aluminium Heat Sink. Dimensions (W x H x D). 369 x 94 x 224mm. Maximum power output (4?). Signal to Noise Ratio. Frequency response (+0dB, -3dB). 10.5V (16V ~ 14.4V allowable). Electro tap: 4 pieces. Ø 5 x 16mm, 6 pieces. M4 x 6mm, 8 pieces.