Audio Terminology And Definitions Dictionary
L Symbol for inductance.
Lacquer The soft disc cut on a lathe from the master tape. It is the first disc stage in the production of LPs.
From the lacquer are made a number of negatives and positives before the negative metal stamper
can be created to press vinyl discs.
Area Network. (See Ethernet.)
LCD flat-panel TVs and video projectors use the same basic Liquid Crystal
Display technology you'll find in cell phone displays, digital camera and
camcorder viewfinders, and computer monitors. LCD panels are composed of two
layers of a polarized glass-like material that are bonded to each other. One
layer is coated with a polymer holding individual crystals. Electric current
that passes through the individual crystals allows the crystals to pass or block
light, depending on the information passed from a central controller. LCD
crystals do not produce their own light and need a light source shining through
the panel (called "backlighting") to produce the image. Newer LCD TVs use
LEDs (light emitting diodes) as this light source. The LED arrays are usually
located on the edges of the display panel (edge-lighting) or in a layer that
covers the rear side of an LCD panel. Although often marketed as "LED TVs,"
LCD TVs use LCD panels to create the image.
for Liquid Crystal on Silicon, a type of LCD display technology.
of left, center, right, surround: the standard channel and speaker configuration
for commercial and home theater sound systems. As the name implies, the L
speaker is located to the left side of the screen; the C speaker is located at,
or close to, the center of the screen; and the R speaker is located to the right
side of the screen. The surround (S) channel is reproduced in commercial movie
theaters by multiple speakers located above, to the sides, and behind the
audience, and in home theaters it is represented by two speakers, usually
located above and either behind or to the sides of the listening/viewing area.
LFE Channel (Low-Frequency
Effects Channel) This is the ".1"channel in a 5.1, 7.1, or 9.1 home theater
system. The LFE channel contains only very low bass information, such as
explosions and collisions, and is typically reproduced by a subwoofer.
A circuit that prevents a signal from exceeding a pre-determined level. A
limiter is a distortion prevention device, and limiters are found in many
Linearity A general term referring to the accuracy of response of an audio component in terms of a particular
measured parameter, such as frequency response. Line Stage: Another name for a preamplifier. A unit that
controls the volume and allows for selection of various inputs (CD player, Tuner, etc).
The relatively low signal level generated by
most audio and audio/video source components, separate processors, etc. Output
voltage for "line level" signals is typically in the 0.5 to 5 volt range,
depending on the component being measured.
Load Electrical resistance is often referred to as the load.
The ability to detect the origin of a given sound. Localization is a complex
process that involves the ear and brain's ability to differentiate between
auditory cues. For example, if a subwoofer plays too far up into the upper
bass/lower midrange, it becomes easier to localize on its position.
Lossless Data Compression
As the name implies, lossless compression
retains all of the data of the original file when it's converted to a smaller
file size. When a lossless file such as a TIFF file is opened, algorithms
restore all the compressed information, creating a duplicate of the original
source file. Lossless compression is generally preferred for creating
high-quality or professional-grade audio and video files, where it's important
to retain fine detail.
Lossy Data Compression
This form of compression always discards
information in order to conserve space and reduce file size. When files are
decompressed, the missing information is reconstructed through algorithms,
usually resulting in some loss of sound quality or image detail when compared to
the original. Generally, the higher the resolution of the compressing file, the
less the degradation. An MP3 file with a resolution of 256 Kbps, for example,
tends to sound more like the source file than one made at 64 Kbps.
A device for converting electrical energy into acoustic energy. (and see Speaker.
The functional opposite of a high-pass filter, low-pass filters progressively
attenuate signals above a pre-determined frequency while "passing" lower
frequency signal components. (See also: high-pass
LP Long Playing record. Usually a 12 inch diameter vinyl disc.
LW Long Wave band (one of three AM radio bands,
the other two being Short Wave and Medium Wave).