What is a car audio system?

May 30, 2023

Car audio system, these are car speakers from the best manufacturers, amplifiers, subwoofers, car stereos, as well as leading brands.

The Head Unit

A high-end audio system uses separate electronic components —a radio tuner, a CD player, a preamplifier, an amplifier—that are connected by various cables. Because space is limited in a car, automakers have had to pack as many of these components as possible into a single device: the head unit. Because of this, the head unit performs many functions, but its two primary functions are to control the overall system volume and the various audio sources in the car.

Head units can also be used to control media players such as an iPod or to navigate a USB flash drive connected to the stereo system. Head units with Bluetooth audio can also play music that is streamed wirelessly from a compatible mobile phone.

In addition to system volume controls, head units typically include basic tone controls, such as bass and treble, to tailor the sound to the listener's taste. Many audio systems also include signal processing that automatically adjusts the volume based on the ambient noise in the vehicle. Some high-end OEM audio systems also have a separate subwoofer and sub-woofer.

Amplifier

A car stereo system must have an amplifier to increase the power of the audio signal so that it is strong enough to drive the speakers and create sound. Amplification is a two-stage process handled by a preamplifier and a power amplifier.

A preamplifier is usually located in the head unit and takes the input from the radio, CD player, or other audio source and prepares it for the power amplifier. This process involves slightly amplifying the audio signal, making it compatible with the power amplifier's input and ensuring that it is immune to noise that may be emitted from other electronics in the vehicle. The power amplifier then takes the low-level signal from the preamplifier and significantly boosts it so that it can drive the speakers and create sound.

Many head units have a small, built-in low-power amplifier that can “drive” small speakers. This allows the audio system to be reduced to just the head unit and a few speakers. But better sound requires more power. So higher-end systems have separate power amplifiers that are mounted away from the head unit due to their size and the heat they generate.

Speakers

Speakers take an amplified electrical signal and convert it into mechanical energy, which moves the speaker cone back and forth to create sound. Sound is essentially vibrations in the air that we hear, and the speaker cone creates these vibrations. The human ear can hear these vibrations in a frequency range from about 20 Hz (very low bass) to 20,000 Hz (very high notes).

Most basic car speakers are designed to be "full range" to cover the entire frequency range. You can get more accurate sound reproduction by using a set of speakers designed to reproduce a smaller range of sound.