Audio Terminology And Definitions Dictionary
is a type of interface between analog video sources and downstream components,
either A/V receivers or displays. With an S-Video connection, black-and-white
(luminance) and color (chrominance) portions of the signal are separated and
transmitted through separate conductors in a cable that is terminated with a
multi-pin DIN-type connector. The result is less color bleeding and more-defined
edges than with a standard analog composite video connection.
(Super Audio Compact Disc) SACD (also called SA-CD) is a
high-resolution audio disc format developed by Sony and Philips and is based on
a proprietary Direct Stream Digital (DSD) format. SACD is capable of more
accurate sound reproduction than the Pulse Code Modulation (PCM) format
currently used for CDs.
In order to convert an analog signal to a digital file, a series of digital
"snapshots" or samples of the signal are made (See also: PCM).
Collectively, these samples represent the digital version of the analog sound.
The higher the sampling rate, the more accurate the sound reproduction. Sampling
rate is usually given in hertz (Hz). CDs use a sampling rate of 44.1 kHz, which
represents 44,100 samples per second. Blu-ray discs can have sampling rates of
up to 96 kHz, or 96,000 samples per second. SACDs (Super Audio CDs) have a
sampling rate of 352 kHz, or 352,000 samples per second.
Short for Syndicat des Constructeurs d'Appareils Radiorecepteurset Televiseurs,
this single-cable audio/video interface format is far more common in Europe than
in North America. SCART connectors have 21 pins, with each pin (or groups of
pins) assigned to pass either an analog video or analog audio signal. SCART
connections can be configured to pass Composite, S-Video or Interlaced (Y, Cb,
Cr) Component and RGB analog video signals and conventional stereo audio. SCART
connectors cannot pass progressive scan or digital video or digital audio
Screen Door Effect The
Screen Door Effect is an LCD artifact that is primarily associated with older
LCD video projectors. LCD projector images are composed of individual pixels
that are separated by black borders. If the projected image is large or the
pixel count is low, these borders become visible and produce the effect of
seeing an image through a "screen door." Recent developments have reduced
the visibility of a pixel's black border and have virtually eliminated this
artifact in recent projectors.
Screening A form of protection of conducting cable from radio interference.
(Sound Designer II) An audio format for Macintosh operating
systems which is often employed by pro-quality sound editing software
applications. SDII files, like AIFF and WAV files, are capable of storing
uncompressed CD-quality audio.
Digital Music Initiative) This standardizes digital music file
specifications. SDMI's primary purpose was to create a uniform copyright
protection protocol that would work with a variety of digital players, software
programs, and download sites. SDMI-compliant devices and files have special
coding in order to recognize and comply with the requirements imposed on
Known variously as Sequential Colour A'Memoire (French), Sequential Color With
Memory (English), or "Something Contrary to American Methods," SECAM
is a video system originally developed in France. While superior to NTSC, SECAM
is not necessarily superior to PAL. SECAM is a 625-line, 50 fields at 25 frames
per second interlaced system with a different method of handling color
components of the video signal. Countries using SECAM include France, Russia,
Eastern Europe, and some parts of the Middle East.
Selectable Output Control
This term describes a cable or satellite
provider's ability to disable 720p/1080i/1080p output from a set-top box via
component video outputs. This ability may be invoked at the discretion of the
movie studios or cable/satellite provider.
Selectivity The ability of a radio tuner to select or separate stations transmitting on nearby frequencies. By
reducing the IF (intermediate frequency) bandwidth to sharpen selectivity, there may be a tradeoff in the form of increased distortion. Some sophisticated tuners provide switchable selectivity so that when two adjacent stations are required to be separated, users may do so by choosing narrow IF selectivity, at other times reverting to wide selectivity to benefit from the natural reduction in
Separation Stereo separation is a measure of the success
in isolating left and right channel stereo signals. The higher the dB specification the better.
Sensitivity has many meanings in audio/video.
It can be the measure of how well a tuner circuit will pick up a weak signal.
This is usually measured in microVolts or dBf (decibels per femtoWatt). Lower
numbers are usually better. Sensitivity can also mean the measure of how loud a
speaker will play with a standard input voltage applied at the terminals. In
this case, sensitivity is usually expressed as "XX dB SPL for 1 watt input (or
2.83 volts, the equivalent at 8 ohms) measured at 1 meter." Sensitivity is not
a measure of a speaker's sound quality; it is only a reflection of how loud it
will play with a given input. (See also: efficiency.)
Series/Parallel See Parallel/Series.
SHN (Shorten) SHN
is a lossless form of compression for digital audio. A Shorten file is only
about half the size of its original WAV or AIFF source. Unlike lossy audio
codecs (such as MP3, WMA, etc.), SHN is capable of reproducing the original
audio signal in its entirety, without removing frequencies. Because of this, SHN
offers significantly better sound quality than MP3. However, since SHN files are
significantly larger than MP3 files, SHN isn't nearly as convenient when storage
space and download times are a concern.
(SNR) SNR is the difference in level, measured in dB, between
a desired signal and residual noise inherent a circuit or an entire component.
All else being equal, higher signal-to-noise measurements usually indicate
better performance potential.
Sine Wave Continuous waveform of a particular frequency (cycles per second).
Single-Beam Laser Transport
An optical laser assembly that uses a single
beam to read the "bumps and pits" off a compact disc (CD). (See also: three-beam
Slit Foil Capacitors
These specially designed power supply capacitors are manufactured for high-end
audio in Great Britain. Their unique properties include a low dielectric loss
with extremely fast time constants (charge/discharge time) in relation to their
storage capacity. In operation, these capacitors emulate the design achievements
of many esoteric products that use a very large number of smaller capacitors to
achieve much the same effect, albeit at substantially higher cost.
The rate at which a filter circuit (high-pass, low-pass, crossover, etc.)
attenuates out-of-band frequencies. Slope is usually measured in decibels per
octave (abbreviated dB/octave). Typical slopes are 6 dB/octave (first order), 12
dB/octave (second order),18 dB/octave (third order), etc.
Smoothing Capacitor An important component in a power supply, the smoothing
capacitor(s) eliminate(s) unwanted ripple, the remains of the positive half cycle
of AC mains following rectification.
of Motion Picture and Television Engineers.
Sound Pressure Level
(dB/SPL) A loudness measurement in decibels. Normal room
conversation is around 60 dB SPL; a loud rock concert is about 100 dB SPL; a jet
airliner taking off is in excess of 130 dB SPL.
(Speaker System or Loudspeaker) A system with three
sub-components: drivers, an enclosure, and (usually) a crossover network.
Speakers are transducers that
convert one form of energy (in this case, an electrical signal) into another
form (acoustical energy). Speaker systems can be freestanding (totally enclosed
in an enclosure or cabinet), they can be placed on a bookshelf or on the floor,
or they can be installed into a wall or ceiling.
Square Wave A waveform designed to simulate a transient impulse such as that of percussion instrument.
Derived from a sine wave, a square wave can be shown by technical analysis to contain a multitude of
harmonics. It is a very difficult test of hi-fi equipment and therefore particularly useful.
Star Earth Grounding
A technique used by designers to ensure that
there is no degradation of sound or acquired "ground loops" by poor "earthing" arrangements. The star earth grounding, or
routes all ground wires to a single point in the design with the resulting wire
arrangement looking somewhat like a star pattern.
Stereo Literally means solid. Usually taken to refer to
Streaming) This term is usually used in connection with audio, video, or
audio/video data and describes one of several methods of transferring data so
that it can be processed as a steady, continuous stream. Streaming technologies
are increasingly important in light of the growing prevalence of high-speed
Internet connections. The "client side," or the receiving end, of the
streaming data must be able to collect it and send it as a steady stream to the
application that is processing the data. After that processing, the data is
converted to sound and/or visual images. This process usually requires a buffer
that temporarily stores the data until downstream components need it. RealAudio
is an example of a program developed for audio streaming.
Stylus The needle part of a cartridge, the tip of which
makes contact with a vinyl record. Elliptical, and super-elliptical (e.g. fine line and Shibata) tipped styli
are preferable to conical styli (found only on the cheapest, most unsophisticated cartridges.
A separate speaker designed specifically for
the accurate reproduction of low-frequency information.
Surround Sound System
A generic term that describes a system designed
to reproduce sound through several (usually four or more) speakers in order to
produce a sense of envelopment in which the listener/viewer is immersed in sound
coming from many directions at once. Almost all home theater systems worthy of
the name provide this capability.
Any speaker used to reproduce the side and/or rear channel information in a home
(Silicon X-tal Crystal Reflective Display) Developed by
Sony, it is a variation of LCOS technology. (See also: LCOS.)
Symmetrical Circuit Layout
A method of circuit configuration that lays out
both the left and right halves of the design in a "mirror image" of each
other. The result is matched electrical performance from both channels for
superb stereo resolution.