Feature: 1. High-frequency to low-frequency technology, accurately restores bass effects, and enhances the shock of the 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 original car host has no audio output, so it is necessary to use a high-quality high-to-low converter, input the high-frequency signal of the host speaker into the high-to-low converter, and convert the high-to-low converter into a low-frequency signal before inputting it into the power amplifier.Although many people think that it is unnecessary to directly lead the low-frequency audio signal from the host to the amplifier or directly use the speaker line high-frequency signal input by using the built-in high-to-low conversion of the amplifier, this connection method generally inputs the internal signal voltage of the amplifier too low by 0.05-0.3V (the amplifier requires the low-frequency signal input voltage to be 0.5-7V), resulting in the amplifier turning on the volume very high, but the speaker sound is still not loud enough, and the impedance led out does not match the 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 the 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 x Diy Solder FM Radio Kit Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.