This product uses a single 9–24V DC power supply and features the TPA3116D2 high-performance digital amplifier chip. It includes a parallel bridged subwoofer amplifier with 120W subwoofer output. It has an external audio input interface, pre-amplification, and subwoofer crossover processing. Two potentiometers allow adjustment of subwoofer volume, subwoofer frequency, and master volume. It operates across a wide voltage range, features a power-saving design, and delivers efficiency over 90%. Compatible power sources include switching power supplies, laptop power adapters, rechargeable batteries, and automotive power supplies. The board is pre-assembled and pre-tested. Connect speakers according to the provided diagram, attach a suitable power supply, and connect the audio source input to begin operation. This board provides mono bass output only; it does not reproduce treble or midrange frequencies. Vocals are faint, with emphasis on low-frequency output. It supports mono and stereo line-level inputs but does not support high-level (speaker-level) inputs. Output will be automatically disabled if the input signal exceeds 1W or if the input signal level is insufficient for proper amplifier operation. Color: Black Material: PCB + Metal Package Contents: 1 × Amplifier Board (with accessories; accessory colors may vary)