HOME

TheInfoList



OR:

Vehicle audio is equipment installed in a car or other vehicle to provide in-car entertainment and information for the vehicle occupants. Until the 1950s it consisted of a simple
AM radio AM broadcasting is radio broadcasting using amplitude modulation (AM) transmissions. It was the first method developed for making audio radio transmissions, and is still used worldwide, primarily for medium wave (also known as "AM band") transmis ...
. Additions since then have included
FM radio FM broadcasting is a method of radio broadcasting using frequency modulation (FM). Invented in 1933 by American engineer Edwin Armstrong, wide-band FM is used worldwide to provide high fidelity sound over broadcast radio. FM broadcasting is cap ...
(1952),
8-track tape The 8-track tape (formally Stereo 8; commonly called eight-track cartridge, eight-track tape, and eight-track) is a magnetic tape sound recording technology that was popular from the mid-1960s to the early 1980s, when the compact cassette, wh ...
players, cassette players, record players, CD players (1984), DVD players,
Blu-ray The Blu-ray Disc (BD), often known simply as Blu-ray, is a digital optical disc data storage format. It was invented and developed in 2005 and released on June 20, 2006 worldwide. It is designed to supersede the DVD format, and capable of st ...
players, navigation systems,
Bluetooth Bluetooth is a short-range wireless technology standard that is used for exchanging data between fixed and mobile devices over short distances and building personal area networks (PANs). In the most widely used mode, transmission power is limi ...
telephone integration, and smartphone controllers like
CarPlay CarPlay is an Apple standard which enables a car radio or head unit to be a display and a controller for an iOS device. It is available on all iPhone models beginning with iPhone 5 running iOS 7.1 or later. According to Apple's website, all m ...
and
Android Auto Android Auto is a mobile app developed by Google to mirror features of an Android device, such as a smartphone, on a car's dashboard information and entertainment head unit. Once an Android device is paired with the car's head unit, the syst ...
. Once controlled from the dashboard with a few buttons, they can now be controlled by steering wheel controls and voice commands. Initially implemented for listening to music and radio, vehicle audio is now part of car
telematics Telematics is an interdisciplinary field encompassing telecommunications, vehicular technologies ( road transport, road safety, etc.), electrical engineering (sensors, instrumentation, wireless communications, etc.), and computer science (multime ...
,
telecommunication Telecommunication is the transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems. It has its origin in the desire of humans for communication over a distance greater than that ...
, in-vehicle security,
handsfree Handsfree is an adjective describing equipment that can be used without the use of hands (for example via voice commands) or, in a wider sense, equipment which needs only limited use of hands, or for which the controls are positioned so that the ...
calling,
navigation Navigation is a field of study that focuses on the process of monitoring and controlling the movement of a craft or vehicle from one place to another.Bowditch, 2003:799. The field of navigation includes four general categories: land navigation ...
, and remote diagnostics systems. The same loudspeakers may also be used to minimize road and engine noise with
active noise control Active noise control (ANC), also known as noise cancellation (NC), or active noise reduction (ANR), is a method for reducing unwanted sound by the addition of a second sound specifically designed to cancel the first. The concept was first develop ...
, or they may be used to augment engine sounds, for instance making a smaller engine sound bigger.


History


Radio

In 1904, well before commercially viable technology for mobile radio was in place,
American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, pe ...
inventor An invention is a unique or novel device, method, composition, idea or process. An invention may be an improvement upon a machine, product, or process for increasing efficiency or lowering cost. It may also be an entirely new concept. If an ...
and self-described "Father of Radio"
Lee de Forest Lee de Forest (August 26, 1873 – June 30, 1961) was an American inventor and a fundamentally important early pioneer in electronics. He invented the first electronic device for controlling current flow; the three-element " Audion" triode v ...
did some demonstration around a car radio at the 1904
Louisiana Purchase Exposition The Louisiana Purchase Exposition, informally known as the St. Louis World's Fair, was an World's fair, international exposition held in St. Louis, Missouri, United States, from April 30 to December 1, 1904. Local, state, and federal funds tota ...
in St. Louis. Around 1920,
vacuum tube A vacuum tube, electron tube, valve (British usage), or tube (North America), is a device that controls electric current flow in a high vacuum between electrodes to which an electric potential difference has been applied. The type known as ...
technology had matured to the point where the availability of
radio receiver In radio communications, a radio receiver, also known as a receiver, a wireless, or simply a radio, is an electronic device that receives radio waves and converts the information carried by them to a usable form. It is used with an antenna. Th ...
s made radio broadcasting viable. A technical challenge was that the vacuum tubes in the radio receivers required 50 to 250
volt The volt (symbol: V) is the unit of electric potential, electric potential difference (voltage), and electromotive force in the International System of Units (SI). It is named after the Italian physicist Alessandro Volta (1745–1827). Defin ...
direct current Direct current (DC) is one-directional flow of electric charge. An electrochemical cell is a prime example of DC power. Direct current may flow through a conductor such as a wire, but can also flow through semiconductors, insulators, or ev ...
, but car batteries ran at 6V. Voltage was stepped up with a vibrator that provided a pulsating DC which could be converted to a higher voltage with a
transformer A transformer is a passive component that transfers electrical energy from one electrical circuit to another circuit, or multiple circuits. A varying current in any coil of the transformer produces a varying magnetic flux in the transformer' ...
, rectified, and filtered to create higher-voltage DC. In 1924, Kelly's Motors in NSW, Australia, installed its first car radio. In 1930, the American
Galvin Manufacturing Corporation Motorola, Inc. () was an American multinational telecommunications company based in Schaumburg, Illinois, United States. After having lost $4.3 billion from 2007 to 2009, the company split into two independent public companies, Motorola ...
marketed a
Motorola Motorola, Inc. () was an American multinational telecommunications company based in Schaumburg, Illinois, United States. After having lost $4.3 billion from 2007 to 2009, the company split into two independent public companies, Motorola ...
branded
radio receiver In radio communications, a radio receiver, also known as a receiver, a wireless, or simply a radio, is an electronic device that receives radio waves and converts the information carried by them to a usable form. It is used with an antenna. Th ...
for $130. It was expensive: the contemporary Ford Model A cost $540. A Plymouth sedan, "wired for Philco Transitone radio without extra cost," was advertised in
Ladies' Home Journal ''Ladies' Home Journal'' was an American magazine last published by the Meredith Corporation. It was first published on February 16, 1883, and eventually became one of the leading women's magazines of the 20th century in the United States. In ...
in 1931. In 1932 in Germany the Blaupunkt AS 5
medium wave Medium wave (MW) is the part of the medium frequency (MF) radio band used mainly for AM radio broadcasting. The spectrum provides about 120 channels with more limited sound quality than FM stations on the FM broadcast band. During the dayti ...
and
longwave In radio, longwave, long wave or long-wave, and commonly abbreviated LW, refers to parts of the radio spectrum with wavelengths longer than what was originally called the medium-wave broadcasting band. The term is historic, dating from the e ...
radio was marketed for 465 Reichsmark, about one third of the price of a small car. Because it took nearly 10 litres of space, it could not be located near the driver, and was operated via a steering wheel remote control. In 1933
Crossley Motors Crossley Motors was an English motor vehicle manufacturer based in Manchester, England. It produced approximately 19,000 cars from 1904 until 1938, 5,500 buses from 1926 until 1958, and 21,000 goods and military vehicles from 1914 to ...
offered a factory fitted car radio for £35. By the late 1930s, push button AM radios were considered a standard feature. In 1946, there were an estimated 9 million AM car radios in use. An FM receiver was offered by Blaupunkt in 1952. In 1953, Becker introduced the AM/FM Becker Mexico with a Variometer tuner, basically a station-search or scan function. In April 1955, the
Chrysler Corporation Stellantis North America (officially FCA US and formerly Chrysler ()) is one of the " Big Three" automobile manufacturers in the United States, headquartered in Auburn Hills, Michigan. It is the American subsidiary of the multinational automotiv ...
announced that it was offering a
Mopar Mopar is the parts, service, and customer care division of the former Chrysler Corporation, now owned by Netherlands-based automobile manufacturer Stellantis. It serves as a primary OEM accessory seller for Stellantis brands under the Mopar bran ...
model 914HR branded
Philco Philco (an acronym for Philadelphia Battery Company) is an American electronics industry, electronics manufacturer headquartered in Philadelphia. Philco was a pioneer in battery, radio, and television production. In 1961, the company was purchased ...
all transistor car radio, as a $150 option for its 1956 Chrysler and Imperial car models. Chrysler Corporation had decided to discontinue its all transistor car radio option at the end of 1956, due to it being too expensive, and replaced it with a cheaper hybrid (transistors and low voltage vacuum tubes) car radio for its new 1957 car models. In 1963, Becker introduced the Monte Carlo, a tubeless solid state radio with no vacuum tubes. From 1974 to 2005, the Autofahrer-Rundfunk-Informationssystem was used by the German ARD network. Developed jointly by the Institut für Rundfunktechnik and Blaupunkt, it indicated the presence of traffic announcements through manipulation of the 57 kHz
subcarrier A subcarrier is a sideband of a radio frequency carrier wave, which is modulated to send additional information. Examples include the provision of colour in a black and white television system or the provision of stereo in a monophonic radio broa ...
of the station's FM signal. ARI was replaced by the
Radio Data System Radio Data System (RDS) is a communications protocol standard for embedding small amounts of digital information in conventional FM radio broadcasts. RDS standardizes several types of information transmitted, including time, station identificati ...
. The AM/FM radio combined with a CD player has remained a mainstay of car audio, despite being obsolescent in non-car applications. In the 2010s,
internet radio Online radio (also web radio, net radio, streaming radio, e-radio, IP radio, Internet radio) is a digital audio service transmitted via the Internet. Broadcasting on the Internet is usually referred to as webcasting since it is not transmitted ...
and
satellite radio Satellite radio is defined by the International Telecommunication Union (ITU)'s ITU Radio Regulations (RR) as a '' broadcasting-satellite service''. The satellite's signals are broadcast nationwide, across a much wider geographical area than t ...
came into competition with FM radio. By this time some models were offering
5.1 surround sound 5.1 surround sound ("five-point one") is the common name for surround sound audio systems. 5.1 is the most commonly used layout in home theatres. It uses five full bandwidth channels and one low-frequency effects channel (the "point one"). Dolb ...
.


Physical media and connectivity

Mobile players for physical media have been provided for
vinyl record A phonograph record (also known as a gramophone record, especially in British English), or simply a record, is an analog sound storage medium in the form of a flat disc with an inscribed, modulated spiral groove. The groove usually starts ne ...
s,
8-track tape The 8-track tape (formally Stereo 8; commonly called eight-track cartridge, eight-track tape, and eight-track) is a magnetic tape sound recording technology that was popular from the mid-1960s to the early 1980s, when the compact cassette, wh ...
s,
cassette tape The Compact Cassette or Musicassette (MC), also commonly called the tape cassette, cassette tape, audio cassette, or simply tape or cassette, is an analog magnetic tape recording format for audio recording and playback. Invented by Lou Ott ...
s,
compact disc The compact disc (CD) is a digital optical disc data storage format that was co-developed by Philips and Sony to store and play digital audio recordings. In August 1982, the first compact disc was manufactured. It was then released in O ...
s, and
MP3 MP3 (formally MPEG-1 Audio Layer III or MPEG-2 Audio Layer III) is a coding format for digital audio developed largely by the Fraunhofer Society in Germany, with support from other digital scientists in the United States and elsewhere. Origin ...
s. The increased sophistication of the vehicle audio system to accommodate such media has made the audio unit a common target of car break-ins, so these are equipped with anti-theft systems too. Attempts at providing mobile play from media were first made with vinyl records, beginning in the 1950s. The first such player was offered by Chrysler as an option on 1956 Chrysler, Desoto, Dodge, and Plymouth cars. The player was developed by CBS Labs and played a limited selection of specially provided 7-inch discs at 16⅔ RPM. The unit was an expensive option and was dropped after two years. Cheaper options using commonly available
45 rpm record In music, a single is a type of release, typically a song recording of fewer tracks than an LP record or an album. One can be released for sale to the public in a variety of formats. In most cases, a single is a song that is released separa ...
s were made by
RCA Victor RCA Records is an American record label currently owned by Sony Music Entertainment, a subsidiary of Sony Corporation of America. It is one of Sony Music's four flagship labels, alongside RCA's former long-time rival Columbia Records; also A ...
(available only in 1961) and
Norelco Norelco is the American brand name for electric shavers and other personal care products made by the Consumer Lifestyle division of Philips. For personal care products marketed outside the United States, Philips used the Philishave trademark ...
. All of these players required extra pressure on the needle to avoid skipping during vehicle movement, which caused accelerated wear on the records. In 1962, Muntz introduced the Wayfarer 4-track cartridge tape player. Celebrities, including Frank Sinatra, had these units installed in their cars. In 1965, Ford and Motorola jointly introduced the in-car
8-track tape The 8-track tape (formally Stereo 8; commonly called eight-track cartridge, eight-track tape, and eight-track) is a magnetic tape sound recording technology that was popular from the mid-1960s to the early 1980s, when the compact cassette, wh ...
player as optional equipment for 1966 Ford car models. In 1968, a dashboard car radio with a built-in
cassette tape The Compact Cassette or Musicassette (MC), also commonly called the tape cassette, cassette tape, audio cassette, or simply tape or cassette, is an analog magnetic tape recording format for audio recording and playback. Invented by Lou Ott ...
player was introduced by Philips. In subsequent years, cassettes supplanted the 8-track and improved the technology, with longer play times, better tape quality, auto-reverse, and
Dolby noise reduction A Dolby noise-reduction system, or Dolby NR, is one of a series of noise reduction systems developed by Dolby Laboratories for use in analog audio tape recording. The first was '' Dolby A'', a professional broadband noise reduction sy ...
. They were popular throughout the 1970s and 1980s. Cassette players were still found in vehicles as late as the 2005-06
Honda CR-V The Honda CR-V (also sold as the Honda Breeze in China since 2019) is a compact crossover SUV manufactured by the Japanese automaker Honda since 1995. The early model was built using the same platform as the Civic. Honda began producing the ...
and 2008
Acura TL The Acura TL is an executive car that was manufactured by Acura, the luxury division of Honda. It was introduced in 1995 to replace the Acura Vigor and was badged for the Japanese-market from 1996 to 2000 as the Honda Inspire and from 1996 to 20 ...
. There have also been vehicle audio units which are able to accept both compact cassettes and CDs. Pioneer introduced the CDX-1, the first car CD (compact disc) player, in 1984. It was known for its improved sound quality, instant track skipping, and the format's increased durability over cassette tapes. Car CD changers started to gain popularity in the late 80s and continuing throughout the 90s, with the earlier devices being trunk-mounted and later ones being mounted in the head unit, some able to accommodate six to ten CDs. Stock and aftermarket CD players began appearing in the late 1980s, competing with the cassette. The first car with an OEM CD player was the 1987
Lincoln Town Car The Lincoln Town Car is a model line of full-size luxury sedans that was marketed by the Lincoln division of the American automaker Ford Motor Company. Deriving its name from a limousine body style, Lincoln marketed the Town Car from 1981 to ...
, and the last new cars in the American market to be factory-equipped with a cassette deck in the dashboard was the 2010 Lexus SC430, and the Ford Crown Victoria. The car cassette adapter allowed motorists to plug in a portable music player (CD player, MP3 player) into an existing installed cassette tape deck. In the early 21st century, compact digital storage media –
Bluetooth Bluetooth is a short-range wireless technology standard that is used for exchanging data between fixed and mobile devices over short distances and building personal area networks (PANs). In the most widely used mode, transmission power is limi ...
-enabled devices,
thumb drive A USB flash drive (also called a thumb drive) is a data storage device that includes flash memory with an integrated USB interface. It is typically removable, rewritable and much smaller than an optical disc. Most weigh less than . Since first ...
s, memory cards, and dedicated hard drives – came to be accommodated by vehicle audio systems. Around this time auxiliary input jacks and USB ports were added to connect
MP3 player A portable media player (PMP) (also including the related digital audio player (DAP)) is a portable consumer electronics device capable of storing and playing digital media such as audio, images, and video files. The data is typically stored ...
s to the vehicle's speakers. Minivans and three-row SUVs have an available rear entertainment system with a
DVD player A DVD player is a device that plays DVDs produced under both the DVD-Video and DVD-Audio technical standards, two different and incompatible standards. Some DVD players will also play audio CDs. DVD players are connected to a television to ...
to entertain passengers. The automobile head unit became increasingly important as a housing for front and
backup In information technology, a backup, or data backup is a copy of computer data taken and stored elsewhere so that it may be used to restore the original after a data loss event. The verb form, referring to the process of doing so, is "back up", ...
dashcams, navis, and operating systems with multiple functions, such as
Android Auto Android Auto is a mobile app developed by Google to mirror features of an Android device, such as a smartphone, on a car's dashboard information and entertainment head unit. Once an Android device is paired with the car's head unit, the syst ...
,
CarPlay CarPlay is an Apple standard which enables a car radio or head unit to be a display and a controller for an iOS device. It is available on all iPhone models beginning with iPhone 5 running iOS 7.1 or later. According to Apple's website, all m ...
and
MirrorLink MirrorLink is a device interoperability standard that offers integration between a smartphone and a car's infotainment system. It transforms smartphones into automotive application platforms where apps are hosted and run on the smartphone while ...
, allowing a smartphone's music library and navigation apps to be controlled via the vehicle's infotainment system. Latest models are coming equipped with features like Bluetooth technology along with HDMI port for better connectivity. Screen size varies from 5-inch to 7-inch for the double Din car stereos.


Active noise control and noise synthesis

The automobile sound system may be part of an
active noise control Active noise control (ANC), also known as noise cancellation (NC), or active noise reduction (ANR), is a method for reducing unwanted sound by the addition of a second sound specifically designed to cancel the first. The concept was first develop ...
system which reduces engine and road noise for the driver and passengers. One or more microphones are used to pick up sound from various places on the vehicle, especially the engine compartment, underside or exhaust pipes, and these signals are handled by a
digital signal processor A digital signal processor (DSP) is a specialized microprocessor chip, with its architecture optimized for the operational needs of digital signal processing. DSPs are fabricated on MOS integrated circuit chips. They are widely used in audio s ...
(DSP) then sent to the loudspeakers in such a way that the processed signal reduces or cancels out the outside noise heard inside the car. An early system focused only on engine noise was developed by Lotus and licensed for the 1992
Nissan Bluebird The is a compact car with a model name introduced in 1957. It has been Nissan's most internationally recognized sedan, in multiple body styles, and is known for its dependability and durability. The Bluebird originated from Nissan's first vehic ...
models sold in Japan. Lotus later teamed with Harman in 2009 to develop a more complete noise reduction system, including road and tire noise as well as chassis vibrations. One benefit of active noise control is that the car can weigh less, with less sound-deadening material used, and without a heavy
balance shaft Balance shafts are used in piston engines to reduce vibration by cancelling out unbalanced dynamic forces. The counter balance shafts have eccentric weights and rotate in opposite direction to each other, which generates a net vertical force. T ...
in the engine. Removing the balance shaft also increases fuel efficiency. The 2013 Honda Accord used an active noise control system, as did the 2013 Lincoln luxury line and the Ford C-Max and Fusion models. Other operating data may also play a part in the DSP, data such as the engine's speed in revolutions per minute (RPM) or the car's highway speed. A multiple source reduction system may reach as much as 80% of the noise removed. The same system may also be used to synthesize or augment engine noise to make the engine sound more powerful to the driver. For the 2015
Ford Mustang The Ford Mustang is a series of American automobiles manufactured by Ford. In continuous production since 1964, the Mustang is currently the longest-produced Ford car nameplate. Currently in its sixth generation, it is the fifth-best selli ...
EcoBoost Fastback and EcoBoost Fastback Premium, an "Active Noise Control" system was developed that amplifies the engine sound through the car speakers. A similar system is used in the F-150
pickup truck A pickup truck or pickup is a light-duty truck that has an enclosed cabin, and a back end made up of a cargo bed that is enclosed by three low walls with no roof (this cargo bed back end sometimes consists of a tailgate and removable covering) ...
.
Volkswagen Volkswagen (),English: , . abbreviated as VW (), is a German Automotive industry, motor vehicle manufacturer headquartered in Wolfsburg, Lower Saxony, Germany. Founded in 1937 by the German Labour Front under the Nazi Party and revived into a ...
uses a Soundaktor, a special speaker to play sounds in cars such as the
Golf Golf is a club-and-ball sport in which players use various clubs to hit balls into a series of holes on a course in as few strokes as possible. Golf, unlike most ball games, cannot and does not use a standardized playing area, and coping wi ...
GTi and
Beetle Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...
Turbo. BMW plays a recorded sample of its motors through the car speakers, using different samples according to the engine's load and power.


Components and terms

The stock system is the OEM application that the vehicle's manufacturer specified to be installed when the car was built. Aftermarket components can also be used. * Head unit: Headunit products includes the screen and buttons and are manufactured mainly in DIN form factor, which refers to ISO 7736. Head units come as single DIN or double DIN. * Connectors for car audio, where ISO 10487 Harness Adapter is used. *
Capacitor A capacitor is a device that stores electrical energy in an electric field by virtue of accumulating electric charges on two close surfaces insulated from each other. It is a passive electronic component with two terminals. The effect of ...
s. * Mobile audio power amplifiers. Amplifiers increase the power level of audio signals. Some head units have built-in stereo amplifiers. Other car audio systems use a separate stand-alone amplifier. Every amplifier has a rated power level sometimes noted on the head unit with the built-in amplifier, or on the label of a stand-alone unit. * Car component speakers which include woofer, tweeter and sub-woofer. * Sound-deadening material is often used in the door cavities and boot area to dampen excess vibration of the panels in the car in response to loud subwoofer bass tones, especially the boot (trunk). * Optical drives with slot-loading mechanism.


Legality

Excessively loud sound systems in automobiles violate the noise ordinance of municipalities, some of which have outlawed them. In 2002, the U.S. Department of Justice issued a guide to
police officer A police officer (also called a policeman and, less commonly, a policewoman) is a warranted law employee of a police force. In most countries, "police officer" is a generic term not specifying a particular rank. In some, the use of the ...
s on how to deal with problems associated with loud audio systems in cars.


Gallery

File:Autoradio Roehre.jpg, A 1950s Philips car radio using both transistor and valves. This model used a range of valves that only required 12 volts for their plate (anode) voltage. File:Chevrolet Corvette Transistorized Hybrid Car Radio-1956.JPG, GM Delco Transistorized "Hybrid" (vacuum tubes and transistors), first offered as an option on the 1956 Chevrolet Corvette car models File:Kenwood KDC-W4527.jpg, A car stereo head unit in a dashboard File:Lincoln Continental Cabriolet photo-58.JPG, 1942 Lincoln Continental Cabriolet radio File:VW Hebmüller (2015-09-12 3701).JPG, Dashboard of VW Hebmüller with Telefunken Radio (1949/50) File:W110 Cockpit.jpg, 1964 Mercedes-Benz W110 190c dashboard with original FM Blaupunkt "Frankfurt" head unit. File:FORD Taunus 17M P2(TL) deLuxe Two door 1958 Radio Blaupunkt Köln.jpg, Blaupunkt Köln Radio - German 1958 Ford Taunus 17M P2 deLuxe File:Ford Sierra CLX 1990 Radio.jpg, 1990 Ford Sierra CLX Radio-Cassette head unit in a dashboard with cassette storage File:1978 AMC Matador sedan red NC detail of factory AM-FM-stereo-8-track unit.jpg, 1978 AMC Matador sedan factory AM-FM-stereo- 8-track unit with an album by
The Blues Brothers The Blues Brothers are an American blues and soul revivalist band founded in 1978 by comedians Dan Aykroyd and John Belushi as part of a musical sketch on ''Saturday Night Live''. Belushi and Aykroyd fronted the band, in character, respecti ...
File:2008-04-16 Car audio drivers.jpg, A set of speaker drivers removed from a passenger vehicle File:Lightning Audio 750 Watts Car Audio Amplifier.JPG, A car audio amplifier File:JLaudiosubwoofers.jpg, Two 10-inch subwoofers in the trunk of a car File:Toyota Camry Factory Integrated (In-Dash) Head Unit.jpg, As technology keeps evolving, head units are now paired with the climate control system and other functions


See also

*
List of car audio manufacturers and brands This list of car audio manufacturers and brands comprises brand labels and manufacturers of both original equipment manufacturer (OEM) and after-market products generally related to in car entertainment that already have articles within Wikipedia. ...
*
Active sound design Active sound design is an acoustic technology concept used in automotive vehicles to alter or enhance the sound inside and outside of the vehicle. Active sound design (ASD) often uses active noise control and acoustic enhancement techniques to a ...


References

{{DEFAULTSORT:Vehicle Audio American inventions Audio players In-car entertainment Radio hobbies Sound production technology Automotive accessories Automotive technologies