MartinLogan Motion Helos 10 - Manual (Page 12)

2101 Delaware Street, Lawrence, Kansas 66046, USA tel 785.749.0133 fax 785.749.5320 www.martinlogan.com
M
a r t i n
L
o g a n
the loudspeaker technology company
©2008 MartinLogan. All rights reserved. Rev. #060408
®
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 gener-
ation 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 another.
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.