A car audio is a device that creates a comfortable driving environment, like at the air conditioner.
The talk of a disc jockey or music from the car audio puts the driver at ease.
Traffic information and news necessary for driving can also be heard.
For car audio, radio and tape player are mainly used. However, due to advances in digital technology, recent models are generally equipped with CD (Compact Disc) players that play the recorded digital signals.
Outline
Stereo
Since humans have two ears, the place from which the sound comes can be judged even when the eyes are closed.
This is because the direction of the sound can be judged according to the difference of the loudness of sound or time lag between when the right ear and left ear receive the sound.
Since ears are on the right and left sides of the head, the sound from the horizontal direction can be judged correctly; however, the sound from the vertical direction cannot be judged as correctly.
In addition, the sound from the front and back can easily be mistaken and the direction of the sound whose frequency is low is difficult to recognize.
A stereo uses the human direction recognition ability as well as the sound volume and time lag from the right and left speaker to create a three-dimensional, realistic sensation.
Construction
The construction of the car audio varies depending on the models and grades. In some cases, the customer may select the components from the dealer options, generally, there are the following components.
1.Radio
The antenna picks up the radio wave transmitted from the radio broadcast station and converts it into the sound signal and sends to the amplifier.
Almost all the recent radios can receive AM/FM broadcast and have an electronic tuner that is controlled by a microcomputer.
2.Tape player/CD player
A tape player reads the analog signal recorded on magnetic tape and sends the sound signal to the amplifier. This device has an auto reverse function, auto pick up function, etc. A CD player reads the digital signal recorded on the optical disc, performs D-A (Digital-Analog) conversion and sends the sound signal to the amplifier. Since digital signal is used, the sound of CD is clearer than that of tape player. This can speedily select songs, which is one advantage of the CD player.
3.Amplifier
The amplifier amplifies (expands) the signal from the radio, tape player, CD player, etc., and sends the signal to the speakers.
4.Speaker
The speaker converts the electrical signal amplified at the amplifier into the (sound) air vibration. To listen to the sound in stereo, there must be at least two speakers.