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
Low
Bass
Lower
Mid High
Mid
Bass Mid
Upper
Bass
Upper
Mid
Below
50Hz
50Hz 300Hz180Hz100Hz 700Hz
100Hz 700Hz300Hz
3KHz
and Above
180Hz 3KHz