Alphabetical search:  A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z   All 
Please enter search here:
Now looking at definitions starting with letter "c"

CAV : Constant Angular Velocity: In a mass storage device, such as a disk, CAV means that the disk assembly rotates at a constant speed, i.e., the data rate will increase for the tracks near the edge, and decrease for tracks near the center spindle. As opposed to CLV.


CD : The CD sampling rate is 44.1kHz and there are 32 bits per sample, so the data rate of the encoded analog data is 1.41Mbps, but the inclusion of parity, synch, and subcode bits raises the real data rate to 4.3Mbps. A CD will hold about 650 Mb, or about 74 minutes of stereo, 16-bit audio. The digital portion of the CD audio system is not stereophonic, but sequential monaural. See also Control and Display signals. Compare with Direct Stream Digital. The CD file format is defined by ISO 9660. For more information on CD standards, please see Sound on Sound, "Compact Disc Formats" by Mike Collins, January 1998. See also SACD. (Super Audio Compact Disc.) The CD specification is specified in "books," each defining the standard for a particular type of CD:

Blue Book: CD Data (CD Extra)

The latest of the books to appear, this specifies the CD Extra format, designed to include CD-ROM data on a standard (audio, Red Book) CD. A CD Extra is actually a multisession CD, containing the audio tracks in its first session, followed by a data track in the second session, etc.

Red Book: System Description Compact Disc Digital Audio (CD-DA)

CD-DA (Digital Audio) Established in 1980 as the first of the books which defined consumer audio on CD. A Red Book CD may have up to 99 tracks; each track is divided into blocks of data called sectors; each sector contains, in addition to audio data, EDC/ECC, and 98 control bytes of PQ subcodes.

Yellow Book: System Description Compact Disc Read-Only Memory (CD-ROM)

CD-ROM (Read Only Memory). Yellow Book extends the Red Book specification by adding two new track types:

CD-ROM Mode 1: Storage of computer data

Mode 1 sectors include an improved ECC for Data.

CD-ROM Mode 2: Compressed audio, video, picture data

Mode 2 (Forms 1 & 2) CD-ROM/XA (Extended Architecture) is used to integrate computer data with compressed audio and/or video, including Photo CD and Karaoke CD.

White Book: System Description Compact Disc Bridge (CD-V)

Developed to cover the CD-V (Video) format, and supported by JVC, Matsushita, Philips, and Sony. These are a special kind of CD-ROM/XA bridge disc that allows the play of films and music videos on a dedicated CD-V player, or on a CD-i player equipped with a CD-V cartridge, or a computer with a CD-ROM/XA drive, an MPEG-1 decoder, and host playback application. The CD medium is modified to record video signals as well as digital stereo audio signals. The video information is recorded in analog form rather than digital. CD-V discs contain full-screen, full-motion video and CD-quality audio, and are independent of any broadcast standard, e.g., NTSC, PAL.

Green Book: System Description Compact Disc Read-Only Memory Extended Architecture (CD-ROM/XA)

Orange Book: System Description Compact Disc Systems Part II: (CD-WO)

A digital standard for recordable, write-once CD. The specification covers both disk-at-once and track-at-once. Many older CD-ROM drives cannot read multisession discs, however, these discs can be converted to a Red/Yellow/Green Book disc by adding a TOC, allowing the disc to be read by any CD player.

CD Single: A small CD-DA that can record 20 minutes of stereo music; it is 80mm in diameter.

CD-DA: CD-Direct Access. Software for writing audio data on hard disk onto a CD-R, for example, Toast™ or Gear.™ Such packages create an unfinished audio session in disc-at-once mode. Digital audio tracks must first be converted to a computer file format like .WAV or AIFF.

CD Extra: Formerly called CD Plus. A solution to mixed-mode CDs, CD Extra inverts the track structure of Mixed Mode by creating two separate sessions: first audio, then data. CD Extra is a part of the Blue Book standard, making Blue Book CDs fully compatible with the Red Book in that Blue Book (data) CDs can be safely used on audio players. The one problem with CD Extra format discs is that its multisession format makes it unusable by first-generation CD-ROM players.

CD-I: (CD Interactive) An extension of Yellow book, allowing discs to contain a mix of audio and video, plus data which the user can control interactively. CD-I discs use Mode 2, Form 1 and Mode 2, Form 2 tracks which, like CD-ROM/XA, enable computer data and compressed audio, video, or pictures to be played back at the same time. CD-I tracks cannot be played on normal CD-ROM drives, but specialized CD-I players can play audio CDs, CD+G, Photo CD, and with a CD-V cartridge, Karaoke CD or CD-V discs.

CD + MIDI: A type of CD which includes both audio data and MIDI data, i.e., a recording of both the sound of a musical performance, as well as the MIDI data used to generate it. This allows the user to "play with the performance" by choosing different patches, etc. This requires a MIDI Out socket on the CD player.

CD-R: See CD.

CD Single: A small CD that can record 20 minutes of stereo music; it is 80mm in diameter.

CD-V: CD Video. The CD medium modified to record video signals as well as digital stereo audio signals. The video information is recorded in analog form, rather than digital, like a small laser disc.

CEDAR : Computer Enhanced Digital Audio Restoration. A British-developed system for the restoration and preservation of old audio recordings. See also NoNoise.

cent : The smallest conventional unit of pitch deviation. One hundred cents equal one half-step. In an instrument, a cent is a term used in discussing pitch resolution; one cent is good, more than six cents is bad. See half-step.

center detent : A notched position in the range of a variable control, allowing the user to return the control to precisely that position, such as the midpoint between the left and right channels in a balance control. Use to denote the flat position on tone controls, etc.

center frequency : The frequency that is boosted or attenuated most by the operation of any parametric equalizer or other similar processing device or circuit. See Q.

center tap : In a transformer, the electrical midpoint of the windings, made accessible for external connection. Used, for example, in delivering power to balanced line condenser microphones. See phantom power, Appendix B.

CG : Computer Graphics.

chain : Also called iron. An integrated system composed of separate audio and/or video recording, processing, or playback circuits and/or devices which are used in conjunction with one another to produce one output result. See B-chain, program chain, signal chain, side chain.

change-over dots : See projection.

change-over projection : See projection.

channel : An independently processed or recorded signal. (1) An electrical signal path. In analog audio (such as a mixer), each channel consists of separate wired components. In the digital domain, channels may share wiring, kept separate through logical operations. (2) A system for independently addressing up to sixteen separate MIDI devices over a single MIDI cable. MIDI provides definitions for 16 channels which transmit not audio signals, but digital control signals for triggering synthesizers and other devices. MIDI data are associated with a particular channel by virtue of a Channel ID Number that is interwoven with other MIDI data being recorded. A track holds data that (depending on the sequencer) may or may not be restricted to one MIDI channel. MIDI’s 16-channel limitation has been overcome by employing multiple independent MIDI ports that each route sixteen channels, offering the possibility of hundreds of channels. (3) The left or right signals of a stereo audio system, or the left, right, center, surround and/or subwoofer signals of a multichannel system, such as LCRS or 5.1. (4) In film, A complete, self-sufficient recording setup. A production channel would include a recorder, mixer, microphones, headsets, etc. A transfer channel would include a 1/4" tape deck, a 35mm mag recorder, a resolver, and a monitoring system.

channel assignment matrix : In a recording console, the group of buttons or switches by which the signal from any input channel can be assigned to one or more busses, and thereby be sent to one or more tracks of the multitrack recorder.

channel bit rate : The actual bits being read from a digital medium are greater than the number strictly required to encode the audio signal. This is because of ECC and synchronization bits, etc. For example, with a CD, the audio bit rate is 1.41Mbps, but the channel bit rate is actually three times as high, 4.32Mbps.

channel insert : An insertion point in a mixer channel which opens up the signal path and allows an outboard device to be inserted in-line. The output point (the place where the signal is routed to the outboard device) is called the channel insert send, and the place where the effected comes back into the mixer is called the channel insert return. The actual point at which the channel signal path is broken with the insert connection is not standard among all consoles. Some are between the preamp and equalizer sections, some after the equalizer, but before the fader, and some are post-fader. Some are switchable with an internal jumper or other modification. If, for example, the channel insert send is post-fader, the fader setting will affect the action of a compressor that is inserted into the channel’s signal path. On the other hand, a post-fader insert is good when it is desirable to send a single channel’s signal direct to a tape track, making the fader into a convenient record-level control. See normalled connection.

channel message : A class of MIDI messages which only affect devices on a MIDI network set to a particular channel, i.e., all non-system messages. Channel messages may be of either Channel Mode or Channel Voice type. See MIDI.

channel mode : See MIDI mode.

channel path : The record section of the signal chain in a mixer. See also monitor path.

channel pressure : A type of MIDI channel message that is applied equally to all of the notes on a given channel; the opposite of poly pressure, in which each MIDI note has its own pressure value. Also called aftertouch, channel pressure is generated on keyboard instruments by pressing down on a key or keys while they are resting on the keybed. Also called channel key pressure.

channel separation : Channel separation refers to the amount of crosstalk between the channels of a stereo system. It is the inverse of interchannel crosstalk, as measured in decibels. A small amount of crosstalk is equivalent to a large channel separation.

channel strip : One of multiple identical sections in a mixering console from the mic preamp and phantom power (if present) to the bus outputs, and typically includes the input pad, EQ, and signal routing, including pan, effect sends and effects returns, and main channel fader, and optionally an automation interface. There is one channel strip per mixer input.

Channel Voice : A classification of MIDI channel message relating specifically to a musical performance, where features of the performance (notes, articulation, etc.) are individually described by a unique message. Channel Voice messages include Note On, Note Off, Polyphonic Key Pressure, Channel Pressure, Program Change, Pitch-bend, and Controller Change. These messages all include a specific channel number, allowing similar messages to address different devices on the same MIDI network. The message will only be implemented by a receiving device whose channel number matches that of the message.

channelize : See MIDI mapping.

characteristic impedance : See termination.

Previous 25 Hits   Next 25 Hits

site design Dan Rugh and Steve Kunath