RXM-F3 1600 Watt Marine/Boat 4 Channel Amplifier Amp+Pa Microphone By admin in rxm-f3 January 4, 2024 If water gets sprayed on the amplifier you will not have to worry. CH3 & CH4 Low Pass 50Hz – 3KHz. CH3 & CH4 High Pass 15Hz – 1KHz. CH1 & CH2 High Pass 50Hz – 300Hz, 500Hz – 3Khz (x10). Fully Adjustable 12dB Bass Equalizer.