The role of car audio high to low 1. High to low: Used to convert the high-level audio voltage output by the speaker into a low-level audio signal for input by other power amplifiers. 2. Common "high to low" converters are roughly divided into passive and active types. Passive high-to-low does not need to be connected to the battery. The high signal has recently gone out, and the middle is a few resistors. So to be precise, passive high to low should be called an attenuator. Active high-to-low requires battery power supply. The high signal is converted into a low signal through an amplifier circuit. It belongs to an audio amplifier that plays a role of reduction. Some active high-to-low with volume adjustment are actually the principle of the power amplifier. 3. It is not necessary to use high-to-low in the audio system. Only when the original car host does not have RCA output, you can consider installing a high-to-low to solve this problem, but the ordinary high-to-low will be Some audio signals are lost.