This noise is generated from the ignition switch of the vehicle, motor, switch, relay, lightning, etc.
AGC circuit (Automatic Gain Control circuit)
This is a circuit to correct the strength of the radio wave.
ATC circuit (Automatic Tone Control circuit)
This is a circuit at the FM radio. While FM broadcast is received, it decreases the uncomfortable sound (white noise) when the radio wave is weak.
ASC circuit (Automatic Separation Control circuit)
This is a circuit at the FM radio. While stereo broadcast is received, this circuit decreases the noise by automatically controlling the degree of separation between the right and left channels according to the radio wave strength from the broadcast. Based on that the monaural broadcast is easier to hear than the stereo broadcast when the radio wave is weak. As the radio wave becomes weaker, this circuit gradually switches from the stereo to monaural.
S/N ratio (Signal to Noise ratio)
S indicates signal and N indicates noise. This shows the ratio of signal level to noise level in dB. For example, when the signal is 100 and the noise is 1, the S/N ratio becomes 40 dB. As the number becomes larger, the quality is better.
This is a device that divides a frequency band (between the low-range and the high-range) of the audio into 5 to 12 bands. The device can adjust the sound pressure of each frequency band. According to this device, the acoustic characteristic in the cabin can be adjusted freely depending on the vehicle shape or personal taste.
Products that are disassembled from the stereo system by function such as speaker, radio, tape player, and CD player, and become independent components.
Automotive Audio System Terminology