1. Dual-channel input, subwoofer output, output to the amplifier can not be directly connected to the speaker
2. Multi-level filtering, better bass effect
3.Phase adjustment
4. Potentiometer from left to right: frequency adjustment, bass volume adjustment
5. Cut-off frequency: 22HZ-240HZ
6. Potentiometer axis center spacing: 3cm
7.pcb size: 62*26.5mm
Audio input: mono or dual-channel
Audio output: mono