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Arrow Manual Glossary 247
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.
S/MUX (sometimes written as “S-MUX”) Abbreviation for Sample Multiplexing. S/MUX
is a method for transmitting two channels of high sample rate (88.2, 96, 176.4, or 192
kHz) 24-bit digital audio over a legacy optical “lightpipe” ADAT connection, which was
originally designed to carry eight channels of 16-, 20- or 24-bit audio at 44.1 kHz or 48
kHz sampling rate. (See “ADAT” and “Lightpipe”)
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 192 kHz, 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”)
Transcoding Converting one type of digital signal to another (i.e, from AES to SPDIF, or
from ADAT to AES).
Transformer An electronic component consisting of two or more coils of wire wound on a
common core of magnetically permeable material. Audio transformers operate on audible
signal and are designed to step voltages up and down and to send signal between
microphones and line-level devices such as mixing consoles, recorders, and DAWs.
Transient A relatively high volume pitchless sound impulse of extremely brief duration,
such as a pop. Consonants in singing and speech, and the attacks of musical
instruments (particularly percussive instruments), are examples of transients.