Glossary
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D24—Owner’s Manual
Glossary
A/D converter
—An electronic device for converting signals from analog to digital.
Contrast with D/A converter.
ABS
—An abbreviation for Absolute. Contrast with REL.
ADAT interconnect format
—The digital audio interconnect format typically
found on ADAT-compatible digital audio equipment. Eight channels of digital audio
are carried per fiber-optic connection, using Toslink connectors.
AES/EBU interconnect format
—The digital audio interconnect format, estab-
lished by the AES (Audio Engineering Society) and EBU (European Broadcasting
Union), for transferring digital audio data between professional digital audio equip-
ment. Two channels of digital audio (left/odd and right/even) are carried per balanced
line.
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. To prevent aliasing, A/D
converters employ anti-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).
Clipping
—The distortion that occurs when an audio signal exceeds a circuit’s maxi-
mum signal level handling capability.
caused by inputting too large a signal to an audio circuit.
D/A converter
—An electronic device for converting signals from digital to analog.
Contrast with A/D converter.
Digital dither
—A technique used to optimize audio sample truncation, when
high-resolution digital audio is transferred to a lower-resolution system. Digital dither
works by comparing the output of a special pseudorandom number sequence genera-
tor with the lowest data bit of the shortened audio sample and the unwanted bits. The
lowest bit is then rounded up or down prior to D/A conversion.
Drop frame
—The technique of dropping video frames to compensate the accumu-
lative error between 29.97 fps timecode and real time.
Dual AES/EBU mode
—An AES/EBU interconnect mode used with the higher sam-
pling rates of 88.2 kHz and 96 kHz, in which the wordclock frequency is exactly half
that of the sampling rate and each signal is split in two and carried by two channels.
DSP (Digital Signal Processor)
—A chip designed specifically for processing large
amounts of data at high speed and in real time, ideal for digital audio processing.
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.
FF
—Abbreviation for fast forward.
Formatting
—The process that prepares a disk for data storage.
fps
—Abbreviation for frames per second.
FS
—Abbreviation for sampling frequency or rate.
