Alesis 03D, Руководство пользователя

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03D—Owner’s Manual
Glossary
A/D converter
—An electronic device that converts analog signals into digital signals.
AES/EBU format —The digital audio format established by the AES (Audio Engi-
neering Society) and EBU (European Broadcasting Union) that is used to transfer dig-
ital audio data between professional equipment. Two channels of digital audio (left/odd
and right/even) are carried in one connection, usually an XLR-type connection.
AFL (After Fader Listen) —A mixer function that allows monitoring of a signal after
the channel fader. Contrast with PFL.
Aliasing —A type of signal distortion that occurs during A/D conversion if the sam-
pling rate is less than twice that of the highest audio frequency. A/D converters employ
aliasing filters to remove audio frequencies higher than half the sampling rate. See also
Nyquist Sampling Theorem.
Anti-aliasing —In digital audio, a technique used to prevent aliasing in the form of an
anti-aliasing filter before A/D conversion. This filter removes audio frequencies that are
higher than half the sampling frequency (e.g., for a 32 kHz sampling rate, audio fre-
quencies above 16 kHz are filtered).
Bulk Dump —A MIDI function that allows data transfer between MIDI devices. Data
is transmitted as MIDI System Exclusive.
Bus —A common conductor used to collect and distribute audio signals.
CH
—Abbreviation for channel.
Clipping —The unwanted distortion effect of overloading an audio circuit with a sig-
nal that is too large.
Coaxial format —The consumer digital audio format developed by Sony and Philips
that is used to transfer digital audio data between consumer-type digital audio equip-
ment, such as CD players, consumer DAT decks, DCC, and MiniDisc decks. Two chan-
nels of digital audio (left & right) are carried in one connection, usually a phono
connection. This format is also referred to as IEC958 and S/PDIF.
Control Change
—A type of MIDI message that offers real-time control. Typical
Control Changes include Modulation, Volume, Pan, and Portamento.
D/A converter
—An electronic device that converts digital signals into analog signals.
De-emphasis —See Emphasis.
DIO
—Abbreviation of digital input and output.
Dither —The process of adding low-level random noise to audio signals in order to
reduce quantization noise in A/D converters. Dither is also applied during digital audio
wordlength reduction (e.g., 20 to 16 bit conversion).
DSP (Digital Signal Processor)
—A chip designed specifically for processing large
amounts of data at high speed and in real time. This type of processor is ideal for han-
dling digital audio data.
Dynamic mix automation —Mixdown automation where mix settings are adjusted
in real time.
Dynamic range —The difference between the loudest and quietest signal levels in a
system. In an audio device, usually the difference between the maximum output level
and the residual noise floor. In a digital system, the available dynamic range is deter-
mined by the data resolution, about 6 dB per digital bit. Hence, a 16-bit system theo-
retically provides a 96 dB dynamic range.