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48,000 Hz
In digital audio, 48,000 Hz (also represented as 48 kHz or DVD Quality) is a common sampling rate. It has become the standard for professional audio and video. 48 kHz is evenly divisible by 24, a common frame rate for media, such as film, unlike 44.1 kHz. Origin In the late 1970s, digital audio didn't yet have a standard for a sampling rate, with proprietary sampling rates ranging from 32 kHz up to 50 kHz. As the use of digital audio increased, it became apparent that standardization on a single sampling rate was needed, which started to be worked on in 1981. A variety of requirements had to be considered before deciding on a sampling rate. Principally, the samplling rate had to be at least double the maximal frequency carried (as per the Nyquist–Shannon sampling theorem) — at least 40 kHz to roughly cover all human-audible frequencies without aliasing distortion. The sampling rates under consideration ranged between 45 kHz and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Audio
Digital audio is a representation of sound recorded in, or converted into, digital signal (signal processing), digital form. In digital audio, the sound wave of the audio signal is typically encoded as numerical sampling (signal processing), samples in a continuous sequence. For example, in CD audio, samples are taken 44,100 Hertz, times per second, each with 16-bit audio bit depth, resolution. Digital audio is also the name for the entire technology of sound recording and reproduction using audio signals that have been encoded in digital form. Following significant advances in digital audio technology during the 1970s and 1980s, it gradually replaced comparison of analog and digital recording, analog audio technology in many areas of audio engineering, record production and telecommunications in the 1990s and 2000s. In a digital audio system, an analog signal, analog electrical signal representing the sound is converted with an analog-to-digital converter (ADC) into a digital ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frames Per Second
A frame is often a structural system that supports other components of a physical construction and/or steel frame that limits the construction's extent. Frame and FRAME may also refer to: Physical objects In building construction *Framing (construction), a building term known as light frame construction * Framer, a carpenter who assembles major structural elements in constructing a building *A-frame, a basic structure designed to bear a load in a lightweight economical manner ** A-frame house, a house following the same principle * Door frame or window frame, fixed structures to which the hinges of doors or windows are attached *Frame and panel, a method of woodworking *Space frame, a method of construction using lightweight or light materials *Timber framing, a method of building for creating framed structures of heavy timber or willow wood In vehicles * Frame (aircraft), structural rings in an aircraft fuselage * Frame (nautical), the skeleton of a boat * Bicycle frame, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Audio
Digital audio is a representation of sound recorded in, or converted into, digital signal (signal processing), digital form. In digital audio, the sound wave of the audio signal is typically encoded as numerical sampling (signal processing), samples in a continuous sequence. For example, in CD audio, samples are taken 44,100 Hertz, times per second, each with 16-bit audio bit depth, resolution. Digital audio is also the name for the entire technology of sound recording and reproduction using audio signals that have been encoded in digital form. Following significant advances in digital audio technology during the 1970s and 1980s, it gradually replaced comparison of analog and digital recording, analog audio technology in many areas of audio engineering, record production and telecommunications in the 1990s and 2000s. In a digital audio system, an analog signal, analog electrical signal representing the sound is converted with an analog-to-digital converter (ADC) into a digital ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audiophile
An audiophile (from + ) is a person who is enthusiastic about high-fidelity sound reproduction. The audiophile seeks to achieve high sound quality in the audio reproduction of recorded music, typically in a quiet listening space in a room with good acoustics. Audiophile values may be applied at all stages of music reproduction—the initial audio recording, the production process, the storage of sound data, and the playback (usually in a home setting). In general, the values of an audiophile are seen to be antithetical to the growing popularity of more convenient but lower-quality music, especially lossy digital file types like MP3, lower-definition music streaming services, laptop or cell phone speakers, and low-cost headphones. The term '' high-end audio'' refers to playback equipment used by audiophiles, which may be bought at specialist shops and websites. High-end components include turntables, digital-to-analog converters, equalization devices, preamplifiers and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aliasing
In signal processing and related disciplines, aliasing is a phenomenon that a reconstructed signal from samples of the original signal contains low frequency components that are not present in the original one. This is caused when, in the original signal, there are components at frequency exceeding a certain frequency called Nyquist frequency, f_s / 2, where f_s is the sampling frequency ( undersampling). This is because typical reconstruction methods use low frequency components while there are a number of frequency components, called aliases, which sampling result in the identical sample. It also often refers to the distortion or artifact that results when a signal reconstructed from samples is different from the original continuous signal. Aliasing can occur in signals sampled in time, for instance in digital audio or the stroboscopic effect, and is referred to as temporal aliasing. Aliasing in spatially sampled signals (e.g., moiré patterns in digital images) is referre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Audio Signal Processing
Audio signal processing is a subfield of signal processing that is concerned with the electronic manipulation of audio signals. Audio signals are electronic representations of sound waves—longitudinal waves which travel through air, consisting of compressions and rarefactions. The energy contained in audio signals or sound power level is typically measured in decibels. As audio signals may be represented in either Digital signal (signal processing), digital or analog signal, analog format, processing may occur in either domain. Analog processors operate directly on the electrical signal, while digital processors operate mathematically on its digital representation. History The motivation for audio signal processing began at the beginning of the 20th century with inventions like the telephone, phonograph, and radio that allowed for the transmission and storage of audio signals. Audio processing was necessary for early radio broadcasting, as there were many problems with stud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-resolution Audio
High-resolution audio is a term for music files with bit depth greater than 16-bit and sampling frequency higher than 44.1 kHz or 48 kHz used in CD and DVD formats. The Audio Engineering Society (AES), Consumer Technology Association (CTA) and Japan Audio Society (JAS) set 24-bit/96 kHz as the minimum requirement to fulfill the standard. The Recording Academy Producers & Engineers Wing also cites 24-bit/96 kHz as the preferred resolution for tracking, mixing and mastering audio. It is supported by media formats such as DVD-Audio, DualDisc and High Fidelity Pure Audio, download stores like Bandcamp, HDtracks and Qobuz, and streaming platforms including Apple Music, Amazon Music and Tidal. Research into high-resolution audio began in the late 1980s and recordings were made available on the consumer market in 1996. Other bit depth/sample rate combinations that are often marketed as "high-resolution" include 1-bit/2.8224 MHz ( DSD), 20-bit/44.1 kHz ( HDCD), 24-bit/44 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rainbow Books
The Rainbow Books are a collection of CD format specifications, generally written and published by the companies involved in their development, including Philips, Sony, Matsushita and JVC, among others. A number of these specifications have been officially adopted by established standards bodies, including the ISO, IEC, and ECMA. ''Red Book'' (1980) *CD-DA (''Digital Audio'') – originally published by Philips and Sony in 1981, it was later standardized as IEC 60908:1987 and later IEC 60908:1999. ** CD-Text – a 1996 extension to CD-DA **CD-MIDI – part of the original Red Book standard ** CD+G (''plus Graphics'') – an extension of the Red Book specifications used mainly for karaoke ***CD+EG (''plus Extended Graphics'') – an extension of CD+G ''Yellow Book'' (1983) *CD-ROM (''Read-Only Memory'') – originally developed by Philips and Sony, it was standardized as ISO/IEC 10149 in 1988 and ECMA-130 in 1989 **CD-ROM XA (''eXtended Architecture'') – a 1991 ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PCM Adaptor
A PCM adaptor is a device that encodes digital audio as video for recording on a videocassette recorder. The adapter also has the ability to decode a video signal back to digital audio for playback. This digital audio system was used for Mastering (audio), mastering early compact discs. Operation High-quality pulse-code modulation (PCM) audio requires a significantly larger Bandwidth (signal processing), bandwidth than a regular analog audio signal. For example, a 16-bit PCM signal requires an analog bandwidth of about 1-1.5 MHz compared to about 15-20 kHz of analog bandwidth required for an analog audio signal. A standard analog audio recorder cannot meet this requirement. One solution arrived at in the early 1980s was to use a videotape recorder, which is capable of recording signals with higher bandwidths. A means of converting digital audio into a video format was necessary. Such an audio recording system includes two devices: the PCM adaptor, which converts aud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compact Disc Digital Audio
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'' technical specifications, which is why the format is also dubbed ''"Redbook audio"'' in some contexts. CDDA utilizes pulse-code modulation (PCM) and uses a 44,100 Hz sampling frequency and 16-bit resolution, and was originally specified to store up to 74 minutes of stereo audio per disc. The first commercially available audio CD player, the Sony CDP-101, was released in October 1982 in Japan. The format gained worldwide acceptance in 1983–84, selling more than a million CD players in its first two years, to play 22.5 million discs, before overtaking records and cassette tapes to become the dominant standard for commercial music. Peaking around year 2000, the audio CD contracted over the next decade due to rising popularity and revenue from digital downloading, and duri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low-pass Filter
A low-pass filter is a filter that passes signals with a frequency lower than a selected cutoff frequency and attenuates signals with frequencies higher than the cutoff frequency. The exact frequency response of the filter depends on the filter design. The filter is sometimes called a high-cut filter, or treble-cut filter in audio applications. A low-pass filter is the complement of a high-pass filter. In optics, high-pass and low-pass may have different meanings, depending on whether referring to the frequency or wavelength of light, since these variables are inversely related. High-pass frequency filters would act as low-pass wavelength filters, and vice versa. For this reason, it is a good practice to refer to wavelength filters as ''short-pass'' and ''long-pass'' to avoid confusion, which would correspond to ''high-pass'' and ''low-pass'' frequencies. Low-pass filters exist in many different forms, including electronic circuits such as a '' hiss filter'' used in audio, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nyquist Frequency
In signal processing, the Nyquist frequency (or folding frequency), named after Harry Nyquist, is a characteristic of a Sampling (signal processing), sampler, which converts a continuous function or signal into a discrete sequence. For a given Sampling (signal processing), sampling rate (''samples per second''), the Nyquist frequency ''(cycles per second'') is the frequency whose cycle-length (or period) is twice the interval between samples, thus ''0.5 cycle/sample''. For example, audio compact disc, CDs have a sampling rate of 44100 ''samples/second''. At ''0.5 cycle/sample'', the corresponding Nyquist frequency is 22050 ''cycles/second'' (hertz, Hz). Conversely, the Nyquist rate for sampling a 22050 Hz signal is 44100 ''samples/second''. When the highest frequency (Bandwidth (signal processing), bandwidth) of a signal is less than the Nyquist frequency of the sampler, the resulting discrete-time sequence is said to be free of the distortion known as aliasing, and the corre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
