MartinLogan Speaker - Manual (Page 21)

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Inductance . The property of an electrical circuit by which
a varying current in it produces a varying magnetic field
that introduces voltages in the same circuit or in a nearby
circuit . It is measured in henrys .
Inductor . A device designed primarily to introduce induc-
tance into an electrical circuit . Sometimes called a choke
or coil .
Linearity .
The extent to which any signal handling process
is accomplished without amplitude distortion .
Midrange .
The middle frequencies where the ear is the
most sensitive .
NAC .
The abbreviation for natural ambience compensation .
Passive .crossover . Uses no active components (transis-
tors, ICs, tubes) and needs no power supply (AC, DC,
battery) to operate . The crossover in a typical loudspeak-
er is of the passive variety . Passive crossovers consist of
capacitors, inductors and resistors .
Phase . The amount by which one sine wave leads or lags
a second wave of the same frequency . The difference is
described by the term phase angle . Sine waves in phase
reinforce each other; those out of phase cancel .
Pink .noise . A random noise used in measurements, as it
has the same amount of energy in each octave .
Polarity . The condition of being positive or negative with
respect to some reference point or object .
RMS . Abbreviation for root mean square . The effective value
of a given waveform is its RMS value . Acoustic power is
proportional to the square of the RMS sound pressure .
Resistance . That property of a conductor by which it opposes
the flow of electric current, resulting in the generation of
heat in the conducting material, usually expressed in ohms .
Resistor . A device used in a circuit to provide resistance .
Resonance . The effect produced when the natural vibra-
tion frequency of a body is greatly amplified by reinforcing
vibrations at the same or nearly the same frequency from
another body .
Sensitivity . The volume of sound delivered for a given
electrical input .
Stator . The fixed part forming the reference for the moving
diaphragm in a planar speaker .
THD . The abbreviation for total harmonic distortion . (See
Distortion)
TIM . The abbreviation for transient intermodulation distortion .
Transducer . Any of various devices that transmit energy
from one system to another, sometimes one that converts
the energy in form . Loudspeaker transducers convert elec-
trical energy into mechanical motion .
Transient . Applies to that which lasts or stays but a short
time . A change from one steady-state condition to anoth-
er .
Tweeter . A small drive unit designed to reproduce only
high frequencies .
Wavelength . The distance measured in the direction of
progression of a wave, from any given point characterized
by the same phase .
White .noise . A random noise used in measurements, as it
has the same amount of energy at each frequency .
Woofer . A drive unit operating in the bass frequencies only .
Drive units in two-way systems are not true woofers but
are more accurately described as being mid/bass drivers .
Glossary of Audio Terms 1