This is a Bluetooth digital amplifier board powered by a single 12-24V DC power supply and uses the TPA3116D2 high-performance digital amplifier chip as its core. One chip is used for parallel bridged subwoofer power output, and the other for left and right channels. It supports a three-channel output of 100W (subwoofer), 50W (left channel), and 50W (right channel). It supports Bluetooth audio reception and an external audio input interface, with preamplifier and bass crossover processing. It also features controls for bass volume, bass frequency, left and right channel volume, treble, function control switch/master volume, and five adjustment potentiometers. It features a wide operating voltage range and a power-saving design, achieving over 92% efficiency. It can be used with a high-performance switching power supply, a laptop switching power supply, a rechargeable battery, a car power bank, or any other spare power source! The board comes pre-soldered and tested. Simply connect the speaker box as shown, connect a suitable power supply, and play music from a Bluetooth audio device or connect the correct audio source to the input. Technical Parameters: Operating Voltage Range: DC 12-24V (current 3-4A, or 19-24V/4A, or 20-24V/8-9A or higher for higher power requirements). If using an AC adapter, add a rectifier and filter to convert to DC power before use. Note: The no-load DC voltage should not exceed 25V (higher voltage will burn the chip). Bluetooth reception range: >10 m (meters), version 5.0. This is the range without obstructions. The phone's Bluetooth performance may also affect the reception range. Audio input sensitivity: 600-800mV, Frequency response: 18Hz-27kHz Speaker impedance: Left and right channels: 2-19 ohms, subwoofer: 2-16 ohms. Suitable for speakers with a power of 10W-300W. Color: Black