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. It uses the Compact Disc Digital Audio format which typically provides 74 minutes of audio on a disc. In later years, the compact disc was adapted for non-audio computer data storage purposes as CD-ROM and its derivatives. First released in Japan in October 1982, the CD was the second optical disc technology to be invented, after the much larger LaserDisc (LD). By 2007, 200 billion CDs had been sold worldwide.
The Compact Disc-Interactive is a digital optical disc data storage format that was co-developed and marketed by Dutch company Philips and Japanese company Sony. It was created as an extension of CDDA and CD-ROM and specified in the Green Book specifications, co-developed by Philips and Sony, to combine audio, text and graphics. The two companies initially expected to impact the education/training, point of sale, and home entertainment industries, but the CD-i is largely remembered today for its video games.
The Sega CD, known as Mega-CD in most regions outside North America and Brazil, is a CD-ROM accessory for the Sega Genesis produced by Sega as part of the fourth generation of video game consoles. It was released on December 12, 1991, in Japan, October 15, 1992, in North America, and April 2, 1993, in Europe. The Sega CD plays CD games and adds hardware functionality such as a faster CPU and graphic enhancements such as sprite scaling and rotation. It can also play audio CDs and CD+G discs.
Compact Disc Digital Audio, also known as Digital Audio Compact Disc or simply as Audio CD, is the standard format for audio compact discs. The standard is defined in the Red Book, one of a series of Rainbow Books that contain the technical specifications for all CD formats. CDDA utilises pulse-code modulation (PCM) and uses a 44,100 Hz sampling frequency and 16-bit resolution, and stores up to 80 minutes of stereo audio per disc.
MiniDisc (MD) is an erasable magneto-optical disc-based data storage format offering a capacity of 60, 74, and later, 80 minutes of digitized audio.
The Compact Cassette, also commonly called a cassette tape, audio cassette, or simply tape or cassette, is an analog magnetic tape recording format for audio recording and playback. Invented by Lou Ottens and his team at the Dutch company Philips, the Compact Cassette was released in August 1963.
Super Audio CD (SACD) is an optical disc format for audio storage introduced in 1999. It was developed jointly by Sony and Philips Electronics and intended to be the successor to the compact disc (CD) format.
A phonograph record, a vinyl record, or simply a record or vinyl is an analog sound storage medium in the form of a flat disc with an inscribed, modulated spiral groove. The groove usually starts near the outside edge and ends near the center of the disc. The stored sound information is made audible by playing the record on a phonograph.
A CD player is an electronic device that plays audio compact discs, which are a digital optical disc data storage format. CD players were first sold to consumers in 1982. CDs typically contain recordings of audio material such as music or audiobooks. CD players may be part of home stereo systems, car audio systems, personal computers, or portable CD players such as CD boomboxes. Most CD players produce an output signal via a headphone jack or RCA jacks. To use a CD player in a home stereo system, the user connects an RCA cable from the RCA jacks to a hi-fi and loudspeakers for listening to music. To listen to music using a CD player with a headphone output jack, the user plugs headphones or earphones into the headphone jack.
Mastering, a form of audio post production, is the process of preparing and transferring recorded audio from a source containing the final mix to a data storage device, the source from which all copies will be produced. In recent years, digital masters have become usual, although analog masters—such as audio tapes—are still being used by the manufacturing industry, particularly by a few engineers who specialize in analog mastering.
The LaserDisc (LD) is a home video format and the first commercial optical disc storage medium, initially licensed, sold and marketed as MCA DiscoVision in the United States in 1978. Its diameter typically spans 30 cm (12 in). Unlike most optical-disc standards, LaserDisc is not fully digital, and instead requires the use of analog video signals.
An album is a collection of audio recordings issued on a medium such as compact disc (CD), vinyl (record), audio tape, or digital. Albums of recorded sound were developed in the early 20th century as individual 78 rpm records collected in a bound book resembling a photo album; this format evolved after 1948 into single vinyl long-playing (LP) records played at 33+1⁄3 rpm.
In digital recording, an audio or video signal is converted into a stream of discrete numbers representing the changes over time in air pressure for audio, or chroma and luminance values for video. This number stream is saved to a storage device. To play back a digital recording, the numbers are retrieved and converted back into their original analog audio or video forms so that they can be heard or seen.
CMJ Holdings Corp. is a music events, online media company and a distributor of up and coming music CDs, originally founded in 1978, which ran a website, hosted an annual festival in New York City, and published two magazines, CMJ New Music Monthly and CMJ New Music Report. The company folded around 2017, but was bought by Amazing Radio in 2019 who announced plans to bring back the CMJ Music Marathon in New York, along with other new live and live-streamed offerings. The letters CMJ originally stood for College Media Journal but was also often considered short for College Music Journal.
Kornelis Antonie "Kees" Schouhamer Immink is a Dutch engineer, inventor, and entrepreneur, who pioneered and advanced the era of digital audio, video, and data recording, including popular digital media such as compact disc (CD), DVD and Blu-ray disc. He has been a prolific and influential engineer, who holds more than 1100 U.S. and international patents. A large portion of the commonly used audio and video playback and recording devices use technologies based on his work. His contributions to coding systems assisted the digital video and audio revolution, by enabling reliable data storage at information densities previously unattainable.
Optical storage refers to a class of data storage systems that use light to read or write data to an underlying optical media. Although a number of optical formats have been used over time, the most common examples are optical disks like the compact disc (CD) and DVD. Reading and writing methods have also varied over time, but most modern systems as of 2023 use lasers as the light source and use it both for reading and writing to the discs. Britannica notes that it "uses low-power laser beams to record and retrieve digital (binary) data."
The loudness war is a trend of increasing audio levels in recorded music, which reduces audio fidelity and—according to many critics—listener enjoyment. Increasing loudness was first reported as early as the 1940s, with respect to mastering practices for 7-inch singles. The maximum peak level of analog recordings such as these is limited by varying specifications of electronic equipment along the chain from source to listener, including vinyl and Compact Cassette players. The issue garnered renewed attention starting in the 1990s with the introduction of digital signal processing capable of producing further loudness increases.
DMP Digital Music Products was one of the first digital recording labels, generally specializing in jazz artists. DMP was founded in 1983 by engineer Tom Jung after leaving Sound 80 recording studios in Minneapolis, Minnesota.
A CD-ROM is a type of read-only memory consisting of a pre-pressed optical compact disc that contains data computers can read—but not write or erase—CD-ROMs. Some CDs, called enhanced CDs, hold both computer data and audio with the latter capable of being played on a CD player, while data is only usable on a computer.
Audio magazine was a periodical published from 1947 to 2000, and was America's longest-running audio magazine. Audio published reviews of audio products and audio technology as well as informational articles on topics such as acoustics, psychoacoustics and the art of listening. Audio claimed to be the successor of Radio magazine which was established in 1917.
