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D.A.T. - Acronym of Digital Audio Tape.

D/A Conversion / Converter: - Digital to Analogue conversion. A converter is a piece of circuitry which acheives this. The quality of conversion is highly dependent on the amount of bits used in the conversion process, hence a 24 bit converter will acheive a much more accurate resolution of the sound than say, an 8 bit converter. This aside a good "rule of thumb" for measuring the quality of D/A and A/D converters is to examine the S/N or "Signal to Noise" ratio of the device in question, which is measured in dBs. The process by which digital data (0’s and 1’s in binary computer language) is reconverted back to an analog (electrical) audio signal. This is how compact disk players play back CDs, and is the same means by which digital synthesizers and samplers play back their sounds through analog outputs such as speakers or headphones.

Daisy Chain: A group of devices or modules connected to each other in a series, where the first one connects to the computer, the second one connects to the first and so on. This would include SCSI, USB and FireWire connectivity.

Damping: Damping refers to the ability of an audio component to stop after the signal ends. For example, if a drum is struck with a mallet, the sound will reach a peak level and then decay in a certain amount of time to no sound. An audio component that allows the decay to drag on too long has poor damping and less definition than one wants. An audio component that is over-damped does not allow the initial energy to reach the full peak and cuts the decay short. Boomy or muddy sound is often the result of under-damped systems. Dry or lifeless sound may be the result of an over-damped system. In the context of reverberation, damping refers to the rate at which the reverberant energy is absorbed by the various surfaces in the environment.

DAO: Disc at Once; a recordable CD method where the session is recorded in one pass without interruption (the laser does not turn off). This is ideal when sending audio recordings to be mastered or pressed as most mastering and/or duplication facilities machines will fail or error out if it detects that the laser was turned off.

DAT - Digital Audio Tape. A tape-based digital audio recording and playback system, developed by Sony, which use a sampling rate of 48 kHz (slightly higher than CDs, which use 44.1 kHz). Audio Industry Standard format for 2 track digital recording. Achieves CD quality audio on a tape about 1/3 the size of a cassette. Abbreviation for “Digital Audio Tape,” it is a digital tape-recording format using a small cassette that provides up to two hours of 16-bit, linear, PCM digital recording at a sampling rate of 32, 44.1 or 48 kHz. A significant advantage that a DAT has over most MiniDisc is that most DAT players will have a digital output, useful when transferring the file to the computer for editing, provided that the soundcard has a digital input. The Edirol UA-1D is the perfect device for this digital transfer with both digital ins and outs. Digital recorders using fixed or stationary heads (such as DCC) are known as S-DAT machines.

DATA COMPRESSION: A system for reducing the amount of data stored by a digital system. Most audio data compression systems are so-called lossy systems as some of the original signal is discarded based on psychoacoustic principles designed to ensure that only components which cannot be heard are lost. A system used to reduce the amount of data needed to represent an audio signal, usually by discarding audio information that is being masked by more prominent sounds.

Data Wheel: A knob that allows you to scroll through Programs and change parameter values. Usually used when a keypad is not available or for fine tuning and scrolling through infinite variables.

Data: Information a computer needs in order to make decisions or carry out a particular action. Information stored and used by a computer.

DAW: Digital Audio Workstation, such as Roland’s VS-2480.

dB (Decibel): A logarithmic measure of sound pressure level, a "Decibel" is one tenth of a "Bel". To put this in human terms, someone with pretty good hearing will be able to pick up sounds from @ 0 - 10dB (a quiet room can be as much as 40dB), and will start to feel pain and possibly sustain hearing damage if they are exposed to levels in excess of 135dB for any length of time (The public address speakers of the kind used at very large concerts may realize this if they are running at their maximum). A reference for the measurement of sound energy. The minimum change in volume that the human ear can perceive. Named after Alexander Graham Bell. A decibel is 1/10th of a Bel. A ratio based measure of the comparative amount of some quality, usually sound level, power or voltage, relative to some reference amount. It is often qualified to indicate what property is being compared i. e. dB(A), dB(v) etc. e. g. One might talk about a signal to noise ratio of 80 dB(v). This would be a comparison between the amplitude of the signal (which we want to hear) and the noise (which we don't). In this case the signal voltage becomes the reference point, (whatever the actual value was) and would be called 0 dB(v), the noise voltage (whatever the actual value was) would therefore be 80 dB(v) smaller. The logarithmic nature of the decibel allows us to compare two values of enormously different magnitudes with conveniently small numbers. e. g. the limits of hearing in terms of absolute pressure level cover the range from 20µPa to 200,000,000 µPa. Any arithmetic on this basis is quite tedious. The same range expressed in dB SPL is 0 -140 dB SPL. Much more convenient.

dB SPL A decibel based unit intend to give an absolute measurement of sound pressure, where 0 dB ="20µPa (micro Pascals). The human range of hearing is related to this scale with 0 dB(SPL) being the threshold of hearing, while 120-140 dB(SPL) (depending on which reference book you use) being the threshold of pain.

dB/Octave: A means of measuring the slope of a filter. The more dBs per octave, the sharper the filter slope. The unit typically used to indicate the slope of a filter, or how fast the frequency response rolls off past the cutoff frequency. Example: A 24 dB/octave filter would attenuate an input signal by 24 dB one octave above the cutoff frequency, by 48 dB two octaves above the cutoff frequency, and so on.

dBm: Variation on dB referenced to 0dB = 1mW into 600Ohms.

dBv: Variation on dB referenced to 0dB = 0.775 volts.

dBV: Variation on dB referenced to 0dB = 1 volt.

dbx: - Form of noise reduction patented by the dbx corporation of the United States. Works by compressing the sound during recording, and expanding it during playback. A commercial encode/decode tape noise reduction system that compresses the signal during recording and expands it by an identical amount on playback.

DC (DIRECT CURRENT) - an electrical current that flows in one direction. Direct Current, which is electrical current where the flow of electrical charge is ALWAYS in the same direction. Whilst almost all household elctricity is AC, the power produced by batteries is invariably DC. See also AC. When looked at through an oscilloscope, DC electricity produces a nice, even Sine Wave.

DCC: Stationary head digital recorder format developed by Philips. Uses a data compression system to reduce the amount of data that needs to be stored.

DCO: Digitally Controlled Oscillator.

DDL: Digital Delay Line.

DECAY - one of the four basic stages of an envelope. Refers to the time the sound takes to settle into its sustain level.

Decay - the period of an envelope during which a sound's attribute (such as volume) stabilizes after the attack has completed. When the sound attribute reaches the end of it's decay, it has reached the sustain period. The progressive reduction in amplitude of a sound or electrical signal over time. In the context of an ADSR envelope shaper, the Decay phase starts as soon as the Attack phase has reached its maximum level. In the Decay phase, the signal level drops until it reaches the Sustain level set by the user. The signal then remains at this level until the key is released, at which point the Release phase is entered.

decoding - making a format readable. MP3 players "decode" MP3 by being able to play the data format as audio. However, the term usually refers to the process of converting MP3 to WAV . This is the process whereby information in a compressed digital audio file is read/expanded so that it can be converted from digital to analog to go to speakers so we can hear. There are software MP3 players that both decode and play MP3 files.

De-esser: - Signal processing device used to cut down on the sibilance or "hissy s's" which can sometime affect speech and singing through a microphone. This is usually through use of the techniques of high frequency compression combined with equalisation.

DEFAULT - the "normal" or "startup" state of a hardware device or software application.

DEFRAGMENT: The process of rearranging the files on a hard disk so that all the files are as contiguous as possible, and that the remaining free space is also contiguous.

DELAY - a common effect in a sampler or synthesizer that mimics the time difference between the arrival of a direct sound and the first reflection to reach the listener's ears. An effect that is used to add depth or space to an audio signal by repeating the input one or more times after a brief pause of a few milliseconds to a few seconds. Delay is also often referred to as echo. - (device which will repeat sound at regular intervals producing echo-like effect). Delay": - see Effects or "FX" Processing . A common effect in a sampler or synthesizer [or effects] that mimics the time difference between the arrival of a direct sound and its audible first reflection. A controllable time parameter giving the ability to start an event only after a predetermined amount of time.The Delay function on the EIII allows you to delay the start of a sound from 0 to 1.5 seconds from the time a key is pressed.

DEOXIDISING COMPOUND: Substance formulated to remove oxides from electrical contacts.

Depth: The amount of modulation. Sometimes called Amount, Width, Intensity or Modulation Index.

Detent: - A stop or catch. In electronics usually placed in a variable resistor such as a the middle point of a "pan" control on a mixing desk, to tell you where the "default" setting is. Physical click stop in the center of a control surface such as a pan or EQ cut/boost knob.

DI BOX: Device for matching the signal level impedance of a source to a tape machine or mixer input.

DI: Short for Direct Inject, where a signal is plugged directly into an audio chain without the aid of a microphone.

DIGITAL AUDIO - the numeric representation of sound. Typically used as the means for storing sound information in a computer or sampler.

Digital Audio Extraction: A method of retrieving audio samples from an audio CD in order to create a computer audio file. This is also known as ripping. This can be accomplished at “CD” quality or MP3 quality MP3, being a digital compression format, will take up less space than a “CD” quality file on a computer audio file.

Digital Audio Tape (DAT): The medium that a machine that records sound digitally uses. They generally use a spinning drum similar to those found in VCR's as opposed to the record and playback heads found on regular analog tape recorders.

DIGITAL DELAY: Digital processor for generating delay and echo effects.

Digital Millennium Copyright Act: This newly enacted law implements two global treaties designed to protect creative works in the digital era. It prohibits the manufacture and distribution of devices the primary purpose of which is to "pick" the electronic "locks" protecting copyrighted material online. This prohibition enables effective enforcement against those seeking to pirate copyrighted music online. The greatest gains from passage of this legislation will be realized internationally. This bill will serve as a model for ratification and implementation of the World Intellectual Property Organization (WIPO) treaties in other countries, where protection of sound recordings online is not sufficient. Formal U.S. ratification of the treaty package helps move the worldwide ratification effort closer to the 30 countries that must ratify the treaties for them to take legal effect. The law also includes important provisions that clarify the rights of copyright owners and the responsibilities of online service providers to guard against piracy online. In addition, the DMCA also contains critical provisions relating to the licensing of music on the Internet and amending the Digital Performance Right in Sound Recordings Act of 1995 (described below).

Digital Performance Right in Sound Recordings Act of 1995: For more than 20 years, the RIAA has been fighting to give copyright owners of sound recordings the right to authorize digital transmissions of their work. Before the passage of the Digital Performance Right in Sound Recordings Act of 1995, sound recordings were the only U.S. copyrighted work denied the right of public performance.

DIGITAL REVERB: Digital processor for simulating reverberation.

Digital Signal Processor: Most signal processors these days are digital. They allow the instant recall of all the parameter settings of the device without having to manually reset all the controls every time a different sound effect is required. Increasingly DSP's are becoming software based, accessed via an audio recording or editing application as a plug-in.

DIGITAL SYNTHESIS - the use of numbers to create sounds. Method most often used in today's synthesizers for generating sounds, as compared to analog method employed previously.

Digital to Analog Converter (DAC): A device which interprets Digital information and converts it to Analog form. All digital musical instruments must have a DAC so that we can hear their output.

Digital versatile disc (DVD) audio and high-density disc: DVD audio is a high-density disc with about seven times the capacity of a CD. The extra capacity in the disc will be used to achieve a high-quality, multi-channel surround sound that is significantly better than current CDs, and may also be used to include features such as text, graphics, video and interactivity. DVD audio discs will require new players, but most, if not all, new DVD players will also play consumers’ existing CD collections.

Digital: - The use of Binary data to represent information, "Binary" meaning that the data (audio, video, whatever) has been reduced to many values which have one of two states, positive and non positive. Positive is represented by 1, and non positve by 0. Each value is known as a "bit". For more on "Digital" within an audio context, see Sample. Equipment that uses quantities represented as binary numbers. In a digital synthesizer every aspect of the sound generation is handled as a numeric calculation. The digital information is not audible and so must be converted to analog form by a DAC before it is output. The phrase “digital audio recording” is contrasted with “analog audio recording.” Long-playing phonograph records are analog recordings and they capture information in a continuously-variable form. Digital, in contrast, involves binary numbers--1's and 0's. Digital encoding can “think” only in terms of the binary numbers 1 (on) and 0 (off), therefore a synthesizer produces sounds by performing mathematical manipulations upon a stream of numbers which are then transformed by a digital-to-analog converter to an electrical signal. In analog there is no conversion taking place, but every time you copy or boost there can be added noise or loss of original content with each pass which does not happen with digital.

DIN CONNECTOR: Consumer multipin signal connection format, also used for MIDI cabling. Various pin configurations are available.

DIN PLUG - a five-pin connector used by MIDI equipment.

Direct and special markets: Targeted consumer environments in which product purchases are made without physically "walking" in to obtain merchandise. Examples include purchases made through mail order, or by responding to television advertising. Some special market programs feature certain conditions or terms under which product is available. Examples include record clubs.

DIRECT COUPLING: A means of connecting two electrical circuits so that both AC and DC signals may be passed between them.

Direct Injection (DI) Box: - Transfomer device which allows a musician to plug an an electronic instrument such as a guitar or bass, directly into one of the inputs of a mixing desk.

Direct time lock (DTL) and enhanced time lock (DTLe): A synchronization standard that allows Mark of the Unicorn's Mac-based sequencer, Performer, to lock to SMPTE through a converter which supports these standards

Directional Pattern: - see Polar Pattern.

DirectX Plug-In - a program that uses Microsoft's DirectX technology to obtain digital audio samples which are then manipulated by applying reverb, compression or some other type of audio signal effect. The output signal may be rendered off-line or generated in real-time while the plug-in's host program performs playback. See Plug-In for more details.

DISC: Used to describe vinyl discs, CDs and MiniDiscs.

disc-at-once (DAO) - single session burning process that cannot be interrupted and does not allow any data to be added once burned on a disc. Does not add 2 second gaps between tracks as does track-at-once recording

DISK: Abbreviation of Diskette, but now used to describe computer floppy, hard and removable disks.

Display: A device that gives information in a visual form.

Distant Miking: A microphone placement technique which involves placing a microphone far from the sound source in order to pick up a high proportion of reverberant sound.

DISTORTION - a process, often found desirable by guitar players, that alters a sound's waveform.

Distributor: A business operation that provides music product from record manufacturers to one stops, rackjobbers, retail and other outlets for ultimate sale to consumers. Distributors often provide marketing and promotion support to record labels and retailers.

DITHER: A system of adding low level noise to a digitized audio signal in such a way as to extend to the low level resolution at the expense of a slight deterioration in noise performance. This tool is used with high-end audio recording programs and audio converters to improve audio quality. It is a mathematical process where a random noise is added to the least significant bit of a digital word to improve audio fidelity when needed. The ability to dither an audio file is absolutely required for good digital audio recording and audio editors such as Sonic Foundry’s Sound Forge and Steinberg’s Wavelab have excellent dithering capabilities.

Divestiture: Removing state investments, usually in the form of pension funds for retired state workers, from entertainment companies producing what some politicians believe is "objectionable" music. This policy threatens the First Amendment and undermines the retirement security of senior citizens by allowing politicians, instead of financial professionals, to decide how to invest state funds.

DMA: Direct Memory Access: Part of a computer operating system that allows peripheral devices to communicate directly with the computer memory without going via the central processor or CPU.

Dolby Digital: A five-channel audio system with all processing in the digital domain consisting of left, center, right and left rear, and right rear channels and optional subwoofer. This is also referred to as Dolby Digital 5.1. Unlike Dolby Prologic in which the rear effects channel’s frequency is limited to approx. 100-7000Hz, Dolby Digital rear channels are specified to contain the full 20-20Khz frequency. When an audio file has already been encoded with Dolby Digital, Edirol’s USB audio interface, the UA-3D has the ability to pass through the signal. An encode/decode tape noise reduction system that amplifies low level, high frequency signals during recording, then reverses this process during playback. There are several different Dolby systems in use: types B, C and S for domestic and semi-professional machines, and types A and SR for professional machines. Recordings made using one of these systems must also be replayed via the same system.

Dollar value: The monetary worth of a stated quantity of shipped product multiplied by the manufacturer’s suggested retail price of a single unit. The value of shipments is given in U.S. dollars.

Domestic market: A term used here to refer to the U.S. consumer market.

DOS: Disk Operating System. Part of the operating system of PC and PC compatible computers

DRIVER: Piece of software that handles communications between the main program and a hardware peripheral, such as a soundcard, printer or scanner. Piece of software that handles communications between the operating system and a hardware peripheral such as a soundcard, printer, MIDI card or scanner.

DRUM MACHINE - an electronic device, usually controllable via MIDI commands, that contains samples of acoustic drum sounds. Used to create percussion parts and patterns. A sample based digital audio device that makes use of the playback capabilities of ROM (read only) memory to reproduce carefully recorded and edited samples of individual instruments which make up the modern drum and percussion set.

DRUM PAD: Synthetic playing surface which produces electronic trigger signals in response to being hit with drum sticks. The playing surface buttons which are designed into a drum machine and played with the fingers. Drum-pad controller: Such a controller offers the performer a larger, more expressive playing surface that can be struck either with the fingers and hands, or with mallets and drum sticks for full expressiveness. Additionally, a drum controller will often offer extensive setup parameters.

Dry" Signal: - Signal which is bereft of any processing, such as eq, gating, reverb and the like. Opposite of "wet" signal. A signal that has had no effects added. When recording audio, this refers to an audio signal which has had no effects added. The best practice is to record dry so one can audition a variety of effects in post production.

DSP - Digital Signal Processing uses mathmatics to operate on a digital signal (such as a digital audio stream) to generate some type of altered output. DSP is used heavily in software and hardware effects processing. DSP chips are found on an increasing number of sound cards to provide extra audio processing power and help relieve the computers CPU of this type of work, much like a 3D graphics accelerator would for rendering 3D graphics. Digital Signal Processing: DSP chips are found in sound cards, synthesizers, effects units, playback and speech synthesis, fax machines, modems, cellular phones, high-capacity hard disks and digital TVs. It is possible that the first DSP was used in the Speak & Spell game in the late 1970s from Texas Instruments. Typically, digital signal processing provides reverb or delay effects, loud speaker processing, EQ limiting and compression as well as feedback destroyers. Other audio uses are amplifiers that simulate concert halls and surround-sound effects for music and home theater. See DSP and Merge. DSP Hardware: DSP hardware frees up a computer’s processing power and speed for other tasks. TC Work’s Powercore is an excellent example of a PCI card which offers DSP processing on the hardware itself—a huge selling feature for this high-end soundcard.

DUBBING: Adding further material to an existing recording. Also known as overdubbing. Within audio files, this refers to adding further material to an existing recording and is also known as overdubbing. See Overdubbing.

DUCKING: A system for controlling the level of one audio signal with another. For example, background music can be made to 'duck' whenever there's a voice over. Ducking is used to automatically reduce signal levels when the level of a source signal exceeds a specified threshold. Often used for voice-over applications, the level of background music is automatically reduced (made to "duck"), allowing an announcer to be heard clearly.

DUMP: To transfer digital data from one device to another. A Sysex dump is a means of transmitting information about a particular instrument or module over MIDI, and may be used to store sound patches, parameter settings and so on.

DVD-A: DVD audio authoring is DVD encoding software. Minnetonka’s discWelder STEEL allows formats supported in the DVD-A specification, including non-encoded, uncompressed surround and or high-resolution stereo (two channels of 24-bit, up to 192 KHz audio), in WAV or AIFF file format. Surround and stereo tracks may be used on the same disc, and a discWelder-burned disc will play on any DVD-A player that supports DVD-R/RW.

Dynamic Allocation: On the EIII, Dynamic Allocation defeats any pre- assigned output channel assignments and assigns the output channels according to a modified circular algorithm.

Dynamic Microphone: - Microphone which works through a diaphragm being attached to a coil which operates within a strong magnetic field. The diaphragm vibrates in response to soundwaves, which, in turn stimulates motion of the coil. The magnetic field causes an electric current to flow through the coil, with a voltage which varies in sympathy with the motion of the diaphragm. This measured change is the transduction of sound waves into an electrical signal. Not as good in terms of fidelity as a condenser type of microphone, but more sturdy and less prone to noise interference, hence it's wide use on stage, or where a certain kind of "grittiness" is required.

DYNAMIC MICROPHONE: A type of microphone that works on the electric generator principle, where a diaphragm moves a coil of wire within a magnetic field. Where a diaphragm moves a coil of wire within a magnetic field and is typically less sensitive than Condenser Microphones where you need more gain.

Dynamic Range The difference in signal level between the loudest and quietest parts of a programme, expressed in decibels. Difference in signal level between the loudest and quietest parts of a performance / recording etc. It is measured in decibels. Incidentally, the dynamic range of the human ear is said to be @ 130 dB. The range of the softest to the loudest sound that can be produced by an instrument. Or the range of the low and high signal levels obtainable by a velocity sensitive keyboard. The greater the Dynamic Range, the more sensitive the keyboard. This refers to the difference between the loudest (maximum output level) and quietest (residual noise floor) sounds produced in an audio system without distortion or clipping. The dynamic range in a digital system is determined by the data resolution, about 6 dB per digital bit. In speech, the range rarely exceeds 40 dB; in music, it is the highest in orchestral works where a broad number of instruments are used, where the range may be as much as 75 dB.

Dynamics Processing: - Processing which alters aspects of the dynamics (difference in sound level) of an audio signal.

Dynamics: The relative loudness or softness of a piece of music. Way of describing the relative levels within a piece of music.

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