MartinLogan Depth subwoofer - Manual (Page 21)

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Inductor. A device designed primarily to introduce inductance
into an electrical circuit. Sometimes called a choke or coil.
Linearity. The extent to which any signal handling process
is accomplished without amplitude distortion.
LFE. The abbreviation for low frequency effects.
Midrange. The middle frequencies where the ear is the
most sensitive.
Passive crossover. Uses no active components (transistors,
ICs, tubes) and needs no power supply (AC, DC, battery)
to operate. The crossover in a typical loudspeaker 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 that is used in a circuit primarily to pro-
vide 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.
SPL. The abbreviation for sound pressure level.
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.
(See 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 electrical
energy into mechanical motion.
Transient. Applies to that which lasts or stays but a short
time. A change from one steady-state condition to another.
Tweeter. A small drive unit designed to produce 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 21