Universal Audio 4-710d Manual page 32

Glossary of Terms
Patch Bay - A passive, central routing station for audio signals. In most recording studios, the
line-level inputs and outputs of all devices are connected to a patch bay, making it an easy matter
to re-route signal with the use of patch cords.
Patch Cord - A short audio cable with connectors on each end, typically used to interconnect
components wired to a patch bay.
Pro Tools - A popular and widely used computer-based digital audio workstation developed and
manufactured by Digidesign. The most current system, Pro Tools | HD, provides hardware and software
that supports multiple channels of high resolution digital audio, at sampling rates of up to 192kHz.
(See "Sample rate")
Quantization Noise - A form of digital distortion caused by mathematical rounding-off errors in the
analog to digital conversion process. Quantization noise can be reduced dramatically by dithering the
digital signal. (See "Dither")
Ribbon Microphone - A type of microphone that works by loosely suspending a small element (usually
a corrugated strip of metal) in a strong magnetic field. This "ribbon" is moved by the motion of air
molecules and in doing so it cuts across the magnetic lines of flux, causing an electrical signal to be
generated. Ribbon microphones tend to be delicate and somewhat expensive, but often have very flat
frequency response.
Sample - A digital "snapshot" of the amplitude of a sound at a single instant in time. The number of
samples taken per second is determined by the device's sample rate. (See "Sample rate")
Sample Rate - The number of samples per second. In digital audio, there are six commonly used
sample rates: 44.1 kHz (used by audio CDs), 48 kHz, 88.2 kHz (2 x 44.1 kHz), 96 kHz (2 x 48 kHz, used
by DVDs), 176.4 kHz (4 x 44.1 kHz), and 192 kHz (4 x 48 kHz). The higher the sample rate, the greater
the frequency response of the resulting signal; however, higher sample rates require more storage
space. (See "kHz")
Sample Rate Conversion - The process of altering a digital signal's sample rate to a different sample
rate. The 4-710d does not perform sample rate conversion.
Single Wire - (sometimes referred to as "Double Fast") The newest revised format of AES/EBU data
transfer that accommodates sample rates of 176.4kHz or 192kHz. The Single Wire standard is similar
in concept to Dual Wire, but instead of using two separate AES cables and connectors, it simply
increases the data rate and sends the signal over one port. The 4-710d supports both Single Wire
mode for the transmission and reception of high resolution AES audio. (See "AES," "Dual Wire," and
"high resolution")
S/MUX - (sometimes written as "S-MUX") An acronym for Sample Multiplexing. SMUX is a method for
transmitting two channels of high sample rate (88.2, 96, 176.4, or 192kHz) 24-bit digital audio over a
legacy optical "light-pipe" ADAT connection, which was originally designed to carry eight channels of
16-, 20- or 24-bit audio at 44.1kHz or 48kHz sampling rate. (See "ADAT" and "Light pipe")
SPDIF - (sometimes written as "S/PDIF") An acronym for "Sony/Philips Digital Interface Format," a
digital audio transfer standard largely based on the AES/EBU standard. Designed to carry two
channels of 16-, 20- or, 24-bit digital audio at sampling rates of up to 192kHz, the most common
SPDIF physical interconnect utilizes unbalanced, 75 ohm video-type coaxial cables terminating at
phono (RCA-type) connectors. (See "AES")
Superclock - A proprietary format used by some early Pro Tools systems to distribute clock signal
running at 256x the system's sample rate, thus matching the internal timing resolution of the
software. (See "Clock" and "Pro Tools")
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