LCD
Liquid Crystal Display. Probably the most common way of showing visual
information on non-computer electronic equipment.
L-Pad
A low resistance (commonly 8 ohms) potentiometer used primarily to control
the input delivered to a speaker. A remote site volume control.
Le
(Measured in millihenries, mH)
The electrical inductance of a speakers voice coil.
Limiter
An electronic compressor with a fixed ratio of 10:1 or greater. The
dynamic action effectively prevents the audio signal from becoming any
larger than the threshold setting. For example, if the threshold is
set for, say, +12 dBu and the input signal increases by 10 dB to +26
dB, the output only increases by 1 dB to +13 dBu, essentially remaining
constant. Used primarily for preventing equipment overloads, thus reducing
clipping distortion.
Line-level
Standard +4 dBu or -10 dBV audio levels. Used in communicating standard
signals between processing devices, such as : receiver to equalizer,
or equalizer to amplifier.
Linear
Linear
phase response
Any system which accurately preserves phase relationships between frequencies.
Linearity
The degree to which a given transducer or amplifier can
produce an equal response within its specified range. This is usually
measured in dB with +or - as small a number as possible indicating the
least amount of variance from the desired flatness.
Listening
Position
A feature which can optimize frequency response and imaging for a particular
position in a vehicle through the use of signal delay.1
Load
The resistance or impedance to which energy is being supplied. In amplifiers,
the speaker or speakers connected to the output of the amplifier.4
Loss
The difference between potential energy output and actual energy output.
Lossy
Compression
A type of
data compression which permanently discards data that humans supposedly
"cannot hear" to create much smaller audio, video and image
file sizes. When the file is decompressed by the recipient, this compression
method replaces the data for the sections it removed with calculated
values to restore the file. The decompressed file is similar but not
identical to the original file.
Loudness
The Sound Pressure Level of a standard sound which appears to be as
loud as the unknown. Loudness level is measured in phons
and equals the equivalent SPL in dB of the standard. [For example, a
sound judged as loud as a 40 dB-SPL 1 kHz tone has a loudness level
of 40 phons. Also, it takes 10 phons (an increase of 10 dB-SPL) to be
judged twice as loud.]
Loudness
Compensation
When played quietly, this switched circuit allows fuller apparent sound
from a system such that the tendancy for human hearing sensitivity to
drop off at certain frequencies is compensated and the full range is
heard.
Loudspeaker
An electro-acoustic transducer that converts electrical audio signals
at its input to audible sound waves at its output.
Low Frequency
Refers to radio frequencies within the 30-300 kHz band. In audio it
usually refers to frequencies in the 20-160 Hz band.
Low Pass Filter
A network of components which attenuate all frequencies above a predetermined
frequency selected by the designer. Frequencies below cut-off are passed
without any effect.
Low
Q
A low Q, or QTS, (reactance) woofer Driver
is desirable for use in a vented enclosure.