The 4 major Components of Car Audio Systems


Car speakers

Driving in a car with no form of audio systems and components such as the head unit, amplifiers, crossovers, and car speakers is like having a body living without a soul. Car speaker systems have become a norm in the automobile sector, where every car designed and manufactured today has a form of stereo audio system installed in it.

Automobile designs are designed with consideration of audio systems and the experience derived by these systems to its passengers and the driver. They have employed acoustic design technologies through thorough research on acoustic materials, car speakers positioning with reference to the occupants’ ears and the travel of sound waves in the car space interior. Automobile designers have set up advanced simulation labs and software to cater for these needs of the best car audio and entertainment features.

Some companies have contracted reputable car audio systems manufacturers to come up with designs that are unique to their customers. They use design data from the car manufacturers in order to come up with the best-sounding systems that can be installed into the car depending on its specifications. A good example of such manufacturers is Boss car speakers’ and JBL car speakers’ manufacturers.

This has created stiff competition amongst manufactures, with the main goal being creating systems that reproduce audio files or music just as they sounded in the production studio. This has posed great challenges leading to advanced technological developments in the car audio systems industry. Some of the major components that form part of the car speaker system include the head units, car speakers, amplifiers and crossovers.

Head unit

Despite investing heavily on car speakers only, car owners tend to spend less time choosing a head unit of which is the most vital and crucial car audio component. The head unit is the mother of all audio experience, where all audio files and music are processed. These units have faced great technological advancements since the early 1930s where Motorola made the first car radio system. Today, they are advanced systems packed with lots of features, unlike just AM radios.

Head units are categorized into two, single-DIN units and double-DIN units. Single-DIN units measure 2 inches by 8 inches, while double-DIN units measure 4-6 inches in height and 8 inches in length. Some units have an internal amplifier, which comes stock, while others require the car owner to buy an external amplifier separately. 

The choice normally depends on the car owner and the size of the dashboard, if it allows the installation of a single-DIN or double-DIN unit. Single-DIN units generally have fewer features as compared to double-DIN units, but all have the same capabilities when it comes to stereo sound production.

The best choice of a head unit for car speakers today should have an inbuilt display output. The display outputs vary from LCD dotted light display to fully colored touchscreen units. Single-DIN units mostly have LCD dotted light screen units, which mostly output the basic functionalities of the head unit.

 These functions include time, song playing, selected connectivity mode, and the radio station channel. This is because they are small screens, which cannot be detailed since it will hinder the visibility of the information displayed. Head units with such types of displays are normally cheap and easy to install because they are small in size and also save on cabin space.

For the full capacitive touchscreen, displays are found in the double-DIN units, which are huge in size and costly to purchase and install into a car. These units come with fully functional color displays that are used for infotainment functionalities. They can display maps, videos, and live videos, such as when paired to parking cameras.

The modern head units of car stereo units have great features such as Bluetooth connectivity with multiple devices, which allows the driver and passengers’ uninterrupted audio experience from the car speakers. This allows two or more phones to be connected to the audio system simultaneously.

These head units also allow for smartphone integration and connectivity. Apple CarPlay and Android Auto are the major smartphone integration apps. They are used to connect the head unit either wirelessly or via cable to the smartphone. This makes the display of the head unit function and display the same content as you would see on the smartphone itself. The driver will have a very easy time operating the system while on the go.

Modern head units have internet connectivity via Wi-Fi or hotspot connection. This allows the driver to load GPS and navigation maps, current weather details and updates are displayed and updated periodically. The driver can navigate a new area safely, select routes to drive, and get updates of current traffic patterns in a town or city. All these are capable if the driver purchases a full display head unit. This has eliminated the monotony tale that head units are just for listening to music and radio.

Head units come with various connectivity input and output modes such as auxiliary ports, USB, CD/DVD drives support, while others have hard drives, which create more space for storing multimedia files. This allows versatility of access to music files; hence the driver does not suffer from a lack of options.

The old car stereo systems were designed and manufactured to include only AM/FM radio frequencies connectivity. Today they allow for Satellite radio where the units do not lose radio frequencies when the driver drives away from the radio transmitters. Internet radio is also accessible such as SiriusXM radio and Pandora radio. These internet radio services allow unlimited access to music, audio files and entertainment features without interruption. The limitation is accessibility in certain continents.

Head units come installed with RGB LED lighting, which makes the system appealing to the eye and beautifies the car interior where it can be matched to suit various mood settings. Inbuilt equalizers are available for enhanced music production and sound quality where the driver can adjust the music bands depending on their taste and liking. Power out of the head unit, to be considered is RMS power output of the unit because some come with pre-amplifiers. If that is not a consideration, the driver can buy a separate amplifier and have it installed. 

Head units come preinstalled with major international languages, which makes it easier for the units to be used worldwide.

Car speakers

Car speakers are the final products of the car stereo system because they output the last sound frequencies to the listener. These speakers are the main point of focus in any car audio system. They are categorized into three major categories that is, high range, mid-range, and low range speakers. This categorization is based on the type of sound the speaker outputs.

  • High-range car speakers, also known as tweeters, produce the high frequencies of the audio file played. The sound produced is normally sharp and clear, and if not well balanced, it may irritate the listeners’ ears. Frequencies produced range from 2 kHz to 20 KHz, where this is achieved by their design and construction.

Tweeters have electrodynamic drivers using a voice coil suspended within a fixed magnetic field. The voice coil produces a varying magnetic field, which works against a fixed magnetic field of a permanent magnet around the suspended cylindrical voice coil and the voice coil and diaphragm attached to it to move, producing high pitch sound.

  • Mid-range speakers are made to produce vocal sound frequencies hence a large audio spectrum and most sounds are -produced by them where they range from 250Hz-2000Hz. These speakers vary in construction from cone type, dome type to compression horn drivers. 

Materials are the major influencers of the output quality and durability of the speaker unit. Speakers made out of high-quality materials tend to outperform those made of cheaper cost-saving materials. Materials mainly used include aluminum, titanium, magnesium and other alloys, while the radiating surfaces are made up of cloth, metal or plastic film.

  • Low range speakers, also known as subwoofers, are car speaker units made to produce bass sound in an audio file. The thumping and throbbing that is audible from a car passing down the street as the driver plays music is the responsibility of low-range speakers. That huge bass is best heard from the low range speakers’, which add more flavor and taste to the music. 
  • Most drivers and in-car music aficionados term this as their best units because they are ground shakers. Subwoofers vary in size from 8-inch to 15-inch speakers. Sound quality is based on the RMS output where a speaker with a high output value has the best bass production. Frequencies range from 20Hz-250Hz.

Car speakers are also subcategorized as full-range speakers or component speakers. Full-range speakers are affordable and have good audio quality, although they cannot produce all sound frequencies as coaxial speakers. They produce a wide range of sound audible to human ears. They are enclosed into cabinets to reduce vibrations and boost the clarity of the speaker unit. They are the most common types of speaker units available.

Component speakers are better as compared to full-range speakers. They are made separately where the tweeters and mid-bass speakers are manufactured into individual units. This allows the units to separate their sound production into distinct sounds; hence they are installed separately in a car interior. Crossovers are used to separate the sound frequencies for each speaker to produce the right sound. Therefore, component speakers have the best audio production, although they come at an added cost for both purchase and installation.


Amplifiers are gadgets installed in a car audio system where they boost the sound from the head unit to be much louder and clearer by the time it gets to the car speakers. Pre-amplifiers, which come stock in a factory head unit purchased together with the car, have less power where most units have around 10 Watts RMS. If the car owner wants to get louder and exciting output out of the speakers, the best solution is to purchase a separate amplifier.


External amplifiers boost all the car speakers, especially the subwoofers that normally require a lot of power supply to get the best audio experience. The most common amplifiers to boost factory car audio systems are 4-channel ones where they can comfortably boost the front and rear speakers.

Speaker level input is the key feature to look at while sourcing a new amplifier either for upgrade or for a completely new system. This will allow easier installation without extra electronic components purchased.


Crossovers are electronic components used in car stereo systems for channeling the right audio frequencies to the right car speakers in a system. They take a single output signal, creating two or three output signals consisting of separate bands of high, mid, and low range frequencies. These frequencies are channeled to the right speakers depending on their range in the car stereo sound system.

Crossovers are categorized into two; that is active and passive crossovers. Active crossovers require power and ground connections, which allows more music fine-tuning and flexibility. They offer a channel for amplification for each speaker, which increases the available power amplification, and the user can control the tonal response over the whole audio spectrum. 

It is connected between the receiver and amplifier and cuts out unwanted frequencies so that the amplifier does not waste power on them. Active crossovers have volume controls for each channel allowing separate control of each speaker or speaker in the channel. Some active crossovers allow equalization to enhance audio output to suit personal taste.

For passive crossovers, they do not require power to filter the sound signal. There are two types; component crossovers and in-line crossovers. Component crossovers are installed between the amplifier and speakers. In car speakers, component speakers come with their own optimized component crossovers. 

Speaker impedance variation leads to changing of the crossover point or frequency response which makes inconsistent sound definition, especially around the vocal regions. In-line are connected between the receiver and amplifier. 

The physical appearance is cylindrical, where they have RCA connectors on each end where they act as connectors to the amplifier. They do not waste power and energy amplifying unwanted signals, making them an inexpensive option to sharpen the car stereo audio output to a crisp and clear sound.