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Test CD
A test CD is a compact disc containing tracks of musical and technical tests and demonstrations. Most of the tracks are made of electronic signals and pure frequencies. The purpose of these specialized compact discs is to make accurate tests and calibrate audio equipment Audio equipment refers to devices that reproduce, record, or process sound. This includes microphones, radio receivers, AV receivers, CD players, tape recorders, amplifiers, mixing consoles, effects units, headphones, and Speaker (audio equipmen .... Releases A wide variety of CD-DA test discs have been produced in the past, and a few are still in production: * Stereophile Test CD 2 * CD-CHECK Test Disc * NAB Broadcast & Audio Test CD, Vol 1 (still in production) * NAB Broadcast & Audio Test CD, Vol 2 (still in production) * Precision Test Signals * The Ultimate Test CD * CBS Records CD-1 Standard Test Disc (with EIA standard signals) * EIAJ CD-1 Standard Test Disc (YGDS 13) (EIAJ Standard CP-308) * Denon A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 October 1982 in Japan and branded as '' Digital Audio Compact Disc''. The format was later adapted (as CD-ROM) for general-purpose data storage. Several other formats were further derived, including write-once audio and data storage ( CD-R), rewritable media ( CD-RW), Video CD (VCD), Super Video CD (SVCD), Photo CD, Picture CD, Compact Disc-Interactive (CD-i) and Enhanced Music CD. Standard CDs have a diameter of and are designed to hold up to 74 minutes of uncompressed stereo digital audio or about 650 MiB of data. Capacity is routinely extended to 80 minutes and 700 MiB by arranging data more closely on the same sized disc. The Mini CD has various diameters ranging from ; they are sometimes used for CD singles, storing up to 24 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Music
Music is generally defined as the The arts, art of arranging sound to create some combination of Musical form, form, harmony, melody, rhythm or otherwise Musical expression, expressive content. Exact definition of music, definitions of music vary considerably around the world, though it is an aspect of all human societies, a cultural universal. While scholars agree that music is defined by a elements of music, few specific elements, there is Elements of music#Selection of elements, no consensus on their precise definitions. The creation of music is commonly divided into musical composition, musical improvisation, and musical performance, though the topic itself extends into #Academic study, academic disciplines, Music journalism, criticism, Philosophy of music, philosophy, and Music psychology, psychology. Music may be performed or improvised using a vast range of musical instrument, instruments, including the human voice. In some musical contexts, a performance or composi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audio Equipment Testing
Audio equipment testing is the measurement of audio quality through objective and/or subjective means. The results of such tests are published in journals, magazines, whitepapers, websites, and in other media. Those who test and evaluate equipment can be roughly divided into two groups: "Objectivists", who believe that all perceivable differences in audio equipment can be explained scientifically through measurement and double-blind listening tests; and the " Subjectivists", who believe that the human ear is capable of hearing details and differences that cannot be directly measured. Summary of Objective versus Subjective Audiophiles, in general: *Both agree that measurements are not a substitute for listening tests. *Both agree that different audio components may have different sound qualities. *Disagree that subjective listeners can overcome placebo and confirmation bias in non-blind listening tests. *Disagree about whether perceived sound quality can be measured through objecti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signal (electrical Engineering)
In signal processing, a signal is a function that conveys information about a phenomenon. Any quantity that can vary over space or time can be used as a signal to share messages between observers. The '' IEEE Transactions on Signal Processing'' includes audio, video, speech, image, sonar, and radar as examples of signal. A signal may also be defined as observable change in a quantity over space or time (a time series), even if it does not carry information. In nature, signals can be actions done by an organism to alert other organisms, ranging from the release of plant chemicals to warn nearby plants of a predator, to sounds or motions made by animals to alert other animals of food. Signaling occurs in all organisms even at cellular levels, with cell signaling. Signaling theory, in evolutionary biology, proposes that a substantial driver for evolution is the ability of animals to communicate with each other by developing ways of signaling. In human engineering, signals are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency
Frequency is the number of occurrences of a repeating event per unit of time. It is also occasionally referred to as ''temporal frequency'' for clarity, and is distinct from '' angular frequency''. Frequency is measured in hertz (Hz) which is equal to one event per second. The period is the interval of time between events, so the period is the reciprocal of the frequency. For example, if a heart beats at a frequency of 120 times a minute (2 hertz), the period, —the interval at which the beats repeat—is half a second (60 seconds divided by 120 beats). Frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio signals ( sound), radio waves, and light. Definitions and units For cyclical phenomena such as oscillations, waves, or for examples of simple harmonic motion, the term ''frequency'' is defined as the number of cycles or vibrations per unit of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audio Equipment
Audio equipment refers to devices that reproduce, record, or process sound. This includes microphones, radio receivers, AV receivers, CD players, tape recorders, amplifiers, mixing consoles, effects units, headphones, and speakers. Audio equipment is widely used in many different scenarios, such as concerts, bars, meeting rooms and the home where there is a need to reproduce, record and enhance sound volume. Electronic circuits considered a part of audio electronics may also be designed to achieve certain signal processing operations, in order to make particular alterations to the signal while it is in the electrical form.Kadis, J. (2011). Introduction to sound recording technology. Informally published manuscript, Stanford Music Department: Center for Computer Research in Music and Acoustics, Stanford University, Stanford, California. Audio signals can be created synthetically through the generation of electric signals from electronic devices. Audio electronics were t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CD-DA
Compact Disc Digital Audio (CDDA or CD-DA), 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 (named for their binding colors) that contain the technical specifications for all CD formats. The first commercially available audio CD player, the Sony CDP-101, was released October 1982 in Japan. The format gained worldwide acceptance in 1983–84, selling more than a million CD players in those two years, to play 22.5 million discs. Beginning in the 2000s, CDs were increasingly being replaced by other forms of digital storage and distribution, with the result that by 2010 the number of audio CDs being sold in the U.S. had dropped about 50% from their peak; however, they remained one of the primary distribution methods for the music industry. In the 2010s, revenues from digital music services, such as iTunes, Spotify, and YouTube, ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Super Audio CD
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. The SACD format allows multiple audio channels (i.e. surround sound or multichannel sound). It also provides a higher bit rate and longer playing time than a conventional CD. An SACD is designed to be played on an SACD player. A ''hybrid SACD'' contains a Compact Disc Digital Audio (CDDA) layer and can also be played on a standard CD player. History The Super Audio CD format was introduced in 1999, and is defined by the ''Scarlet Book'' standard document. Philips and Crest Digital partnered in May 2002 to develop and install the first SACD hybrid disc production line in the United States, with a production capacity of up to three million discs per year. SACD did not achieve the level of growth that compact discs enjoyed in the 1980s, and was not accepted by the m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 October 1982 in Japan and branded as '' Digital Audio Compact Disc''. The format was later adapted (as CD-ROM) for general-purpose data storage. Several other formats were further derived, including write-once audio and data storage ( CD-R), rewritable media ( CD-RW), Video CD (VCD), Super Video CD (SVCD), Photo CD, Picture CD, Compact Disc-Interactive (CD-i) and Enhanced Music CD. Standard CDs have a diameter of and are designed to hold up to 74 minutes of uncompressed stereo digital audio or about 650 MiB of data. Capacity is routinely extended to 80 minutes and 700 MiB by arranging data more closely on the same sized disc. The Mini CD has various diameters ranging from ; they are sometimes used for CD singles, storing up to 24 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
