Low Pass Filter Bass Subwoofer Preamp Amplifier Board Single Power DC 9-32V Bass Description: Note: This board is a preamp board, it can't be directly connected to the speaker. It must be connected to the subsequent stage of an amplifier board for this pre-amp to work. The so-called low-pass filter to filter out the human voice board is more than treble part, retain the low frequency part is amplified to improve the bass reproduction efforts, people will not hear the sound of musical instruments and high-frequency sound during playback. The buyer must understand knowledge of this area. Features: Power supply voltage: DC 9V-32V single power supply Dual channel input, subwoofer output, then the output amp|ifier,can not directly connected to the speaker The multi-stage filter, better bass effect The phase adjustable Potentiometer from left to right: frequency adjustment, bass volume control The cut-off frequency: 22HZ-240HZ Potentiometer shaft center to center spacing: 3cm PCB Size: 62 9* 26.5mm Audio input: mono or two-channel Audio output: Mono(connect with amplifier) Package included: 1PC x Low Pass Filter Bass Subwoofer Pre-AMP Amplifier Board 1PC x Power cable 1PC x Audio Shieklded cable