1. High-frequency to low-frequency technology, accurately restores bass effects, and enhances shock of sound 2. Delay function design ensures synchronization of sound effects and creates an immersive listening experience 3. Optimized for car audio, strong adaptability, easy installation 4. Built-in high-quality modules, efficient subwoofer drive, output strong low-frequency power 5. Stable circuit design, strong anti-interference ability, ensuring quality without distortion Principle of use: The car host has no audio output, so it is necessary to use a high-quality high-to-low converter, input high-frequency signal of host speaker into high-to-low converter, and convert high-to-low converter into a low-frequency signal before inputting it into power amplifier.Although many people think that it is unnecessary to directly lead low-frequency audio signal from host to amplifier or directly use speaker line high-frequency signal input by using built-in high-to-low conversion of amplifier, this connection method generally inputs internal signal voltage of amplifier too low by 0.05-0.3V (the amplifier requires low-frequency signal input voltage to be 0.5-7V), resulting in amplifier turning on volume very high, but speaker sound is still not loud enough, and impedance led out does not match amplifier input impedance, which is easy to cause signal interference and noise. Product parameters: Maximum channel input power 50W output voltage 0.2V-2V output bandwidth 20Hz-20KHz REM maximum output control current 1A Note:If BEM control function is not used, the red, black and blue wires do not need to be connected Color:Black Material:ABS Package Contents: 1 * Diy Solder FM Ra Kit Only above package content, other products are not included. Note: Light reflection and different displays may cause color of item in picture a little different from real thing. The measurement allowed error is +/- 1-3cm.