12.0 Glossary of Terms
Active: Uses electrical power.
Amplifier: An electronic device that increases
the current and/or voltage of a signal, providing
power to the loudspeakers (i.e. power amplifier,
integrated amplifier, receiver).
Bass: The range of audio frequencies below
160Hz, characterized by low pitch.
Crossover: An electronic circuit that divides an
audio signal into different frequency ranges.
Distortion: Any deviation from the original sig-
nal.
Driver: The moving part of a loudspeaker, which
radiates sound energy.
Dynamics: Variations in loudness of sound.
Frequency: A rate of vibration, which corre-
sponds to musical pitch, expressed in Hertz
(Hz).
Full Range: A signal encompassing the entire
frequency spectrum.
Hertz (Hz): A unit equal to one cycle per sec-
ond, used to measure the frequency of a signal
or sound.
High-Pass Filter: A filter that passes only high
frequencies above a lower limit.
Impedance: A measure of the total opposition
to current flow in an alternating current circuit,
measured in ohms.
In Phase: The polarity of an audio signal when
connected as follows: (+) to (+) and (-) to (-).
Integrated Amplifier: A preamplifier and ampli-
fier built into one chassis.
Interconnect Cable: A length of shielded wire
with plugs at both ends for feeding signals from
one electronic device to another.
L.F.E.: "Low Frequency Effects"; The .1 channel
of information recorded on most multichannel
digital sound formats.
Line-Level Connection: Low level RCA/phono
or XLR type connection.
Load: A term used to describe the impedance
that a speaker presents to an amplifier.
Low-Pass Filter: A filter that passes only low
frequencies below a higher limit.
Main Speakers: Front L & R channel speakers,
sometimes referred to as satellites.
Main-In: A line-level RCA/XLR power amplifier
input on the back of a receiver, integrated ampli-
fier or power amplifier.
Midrange: The frequency span in the middle of
the audio range, roughly 160Hz - 1300Hz. Also
used to describe the driver that reproduces
these frequencies.
Ohm: A unit of electrical resistance. That which
opposes an electric current in a conductor. In
audio, a measure of the load presented by a
device to an electrical source.
Out-of-Phase: The polarity of an audio signal
when connected as follows: (+) to (-) and (-) to
(+).
Passive: Uses no electrical power.
Phase: An expression of the relative polarities
of two signals.
Power Handling: The ability of a loudspeaker to
operate without large increases in distortion
when given varying amounts of input power.
Preamplifier: An electronic device that selects
sources and passes line-level signals to an
amplifier.
Pre-Out: A preamp line-level RCA output on the
back of a receiver, integrated amplifier or pre-
amplifier.
Receiver: A preamplifier, amplifier and tuner
built into one chassis.
Satellite: Front L & R speakers when used with
a subwoofer. Referred to as "main speakers".
Sensitivity: A ratio of voltage across the speak-
er load to the acoustic power output, measured
