Just as the invention of the transistor eliminated the need for vacuum tubes, advances in technology allow us to create new and unique entertainment solutions with more and more features. We thought it would be fun to take a quick look at a few important car audio technologies throughout history.
The first car radios used vacuum tubes as integral parts of their tuner and amplifier circuitry. Tubes required high-voltage power supplies and consumed a lot of power. They produce a lot of heat and are fragile. The result was finicky products with limited performance. The first transistor was theorized in 1926 but wasn’t built for the first time until 1947. It wasn’t until 1955 that we saw Chrysler and Philco announce the first automotive transistor radio – the Mopar model 914HR.
The transistor is considered one of the greatest inventions of the 20th century. Transistors improved the efficiency and reliability of electronics components and led to the creation of microchips and ultimately computers. The Apple A11 Bionic CPU, found in the iPhone 8, 8 Plus and iPhone X, has 4.3 million transistors built into it. The Microsoft Xbox One main CPU has more than 7 million transistors inside. More impressively, a 128 gigabyte stick of DRAM memory has more than 137 quadrillion transistors!
Radio was truly the technology that drove car audio systems. The first radio broadcasts were weekly special events that included concerts in 1914 and daily news broadcasts in 1916. On May 20, 1920, XWA – the experimental station of the Canadian Marconi Co. – began regular broadcasts in Montreal. XWA claims status as the first commercial broadcaster in the world. These were all AM (amplitude modulation) stations. FM (frequency modulation) radio was patented in 1933, but it wasn’t until the late ’30s that FM broadcasts became popular. The broadcast of a stereo FM signal was first considered by the FCC in the late 1950s, and a standard was approved in 1961.
The Compact Cassette and 8-Track Tape
Reel-to-reel recording on magnetic tapes was popular in the 1940s but wasn’t suitable for use in mobile applications. The 8-track was preceded by the Stereo-Pak 4-track cartridge in 1962. The endless-loop cartridge could store both sides of a vinyl album. The 8-track, known originally as the Lear Jet Stereo 8 Track Cartridge, was launched by Bill Lear in 1963. In 1965, Ford offered factory and dealer-installed 8-track options on its Mustang and Thunderbird and on several high-end Lincoln vehicles.
Call it a tape or a cassette, the first compact cassette (as we know it) was introduced by the Phillips Corp. in 1963 as a storage medium for dictation machines. Widespread use of the compact cassette in the mid-’70s and the introduction of chromium dioxide (CrO2) as a premium recording medium and Dolby B noise reduction spelled the end of the 8-track.
Most people don’t realize that digital audio (known then as pulse code modulation) was invented in 1937 in Britain and was used in telecommunications. In the late ’60s, Denon pioneered commercial digital recording. The BBC used digital audio transmissions to link its broadcast center to its transmitter in 1972. Sony and Mitsubishi drove the consumer popularization of digital audio in the early ’80s and brought about acceptance by major record companies. The first compact disc was released in 1982 using the Red Book Compact Disc Digital Audio (CD-DA) standard that is still in use today. The first OEM-installed CD players were in the 1987 Lincoln Town Car.
Class D Amplifiers
The benefit of Class D amplifiers is their efficiency and low-to-moderate power levels. Class D amps use high-frequency pulse-width modulation waveforms to switch MOSFETs (metal-oxide-semiconductor field-effect transistors) on and off very quickly to amplify signals. Filter networks on the output of the circuits remove high-frequency noise so that only the audio signal is left to drive our speakers. Class D amplifiers allow manufacturers to produce much more powerful amplifiers that take up very little space. These amplifiers consume less current than their Class AB counterparts.
Computerized Source Units
Around 1980, we saw the first digitally tuned car radios. Mechanical tuning knobs and presets were replaced with vacuum fluorescent displays and electronic buttons. This would lead to computerized source units that included electronically controlled cassette players and equalizers with spectrum displays around 1982. By the late ’80s, with the growing popularity of CD players, having a microcontroller built into a car radio was commonplace.
Around 1992, companies like Alpine and Clarion were selling in-vehicle navigation systems that included LCD screens, and by 1993, digital communication solutions were available to transmit computer information to vehicles. In 1998, Clarion launched the AutoPC in conjunction with Microsoft to become the first in-vehicle computer. Modern multimedia receivers now run embedded versions of Windows and Linux operating systems.
The Apple iPod
The Apple iPod was introduced in the fall of 2001. The original compact digital media players were only compatible with computers running the Apple Macintosh operating system and as such, sales were limited. In 2003, the iPod 3G was launched with a standard USB port instead of Firewire, making it compatible with Windows-based PCs as well. By June 2003, Apple had sold 1 million iPods.
In June 2005, BMW announced that an iPod adapter would be available for the 3 Series, the Z4 Roadster, the X3 and X5 and the Mini Cooper, and was backward compatible to many 2002 models.
By 2005, the iPod was a popular solution for carrying thousands of songs, and Clarion launched its VRX745VD – a single-DIN multimedia receiver with a dedicated iPod interface. The iPod quickly replaced the CD changer as a means of storing a large number of songs in vehicles.
Though incorrectly perceived as a hands-free and audio streaming technology, Bluetooth was created in 1994 as an alternative to RS-232 wired communication. Within the Bluetooth communication standards are dozens of profiles, including fax, cordless telephony, printing, file transfer, dial-up networking and of course, the hands-free and audio distribution profiles that we know and love! In 2002, the Audi R8 was the first to apply Bluetooth technology in a car. DaimlerChrysler, Acura and BMW joined in 2003.
Apple CarPlay and Android Auto
Since the very first car radios were built, people were concerned about them being a distraction. Turning the tuner knob to find a local station meant you weren’t focused on the road in front of you. In the late ’90s, we saw drivers with headsets and earpieces making phone calls while they drove. Adding a headset was a common purchase with a new phone. In the mid-2000s, Bluetooth communication replaced wired hands-free connections.
Data distractions took off in the late ’90s and early 2000s with the Blackberry. When smartphone technology took off in the 2000s, so did text messaging. We now had lots of ways to distract us from our driving duties.
Apple realized that the smartphone was as much of a problem as it was a solution in the early 2010s. In 2013, Siri Eyes Free was offered as a dealer-installed accessory for several Honda and Acura vehicles. In 2014, the Ferrari FF became the first new vehicle to come equipped with Apple CarPlay.
CarPlay is a software application that runs on the multimedia source unit in the vehicle and uses the Siri voice recognition engine built into the iPhone to allow voice commands to be executed. You can send a text message, make a phone call or choose the music you want by simply asking. Turn-by-turn navigation is also included.
The Open Automotive Alliance announced in 2014 that it would introduce a competing technology for Android-based smartphones called Android Auto. The 2015 Hyundai Sonata was the first OEM implementation of Android Auto. Few car audio technologies have rivaled the importance of CarPlay and Android Auto.
Technology for Safety and Entertainment
There have been hundreds, if not thousands, of milestones throughout the 100-plus years of automotive technology advances. These innovations are just a sampling of the way mobile electronics have evolved and changed. If you are looking for the latest and greatest car audio technologies, or simply want to improve the performance of your entertainment system, visit your local mobile electronics specialist retailer.