Jensen Power400 400-Watt 2-Channel Amplifier (Grey) In-Wall Subwoofer Box Variable Low Pass Filters 40240 Hz (12 Db Per Octave) Variable High Pass Filters 40400 Hz (12 Db Per Octave) Variable Bass Boost 0 ~ 12 Db At 45 Hz Low Level Pass Trough Rca'S (Channel 1 & 2 Only)