Fresco Speaker - Manual (Page 18)

18 Glossary of Audio Terms
G
LOSSARY OF
A
UDIO
T
ERMS
AC. Abbreviation for alternating current.
Active crossover. Uses active devices (transistors, ICs,
tubes) and some form of power supply to operate.
Amplitude. The extreme range of a signal. Usually
measured from the average to the extreme.
Arc.
The visible sparks generated by an electrical
discharge.
ATF. The abbreviation for advanced thin film.
Bass.
The lowest frequencies of sound.
Bi-Amplification.
Uses an electronic crossover, or line-
level passive crossover, and separate power amplifiers for
the high and low frequency loudspeaker drivers.
Capacitance. That property of a capacitor which
determines how much charge can be stored in it for
a given potential difference between its terminals,
measured in farads, by the ratio of the charge stored to
the potential difference.
Capacitor. A device consisting of two or more conducting
plates separated from one another by an insulating
material and used for storing an electrical charge.
Sometimes called a condenser.
Clipping.
Distortion of a signal by its being chopped off.
An overload problem caused by pushing an amplifier
beyond its capabilities. The flat-topped signal has high
levels of harmonic distortion which creates heat in a
loudspeaker and is the major cause of loudspeaker
component failure.
CLS. The abbreviation for curvilinear linesource.
Crossover.
An electrical circuit that divides a full
bandwidth signal into the desired frequency bands for the
loudspeaker components.
dB (decibel).
A numerical expression of the relative
loudness of a sound. The difference in decibels between
two sounds is ten times the Base 10 logarithm of the ratio
of their power levels.
DC. Abbreviation for direct current.
Diffraction. The breaking up of a sound wave caused by
some type of mechanical interference such as a cabinet
edge, grill frame or other similar object.
Diaphragm.
A thin flexible membrane or cone that
vibrates in response to electrical signals to produce sound
waves.
Distortion. Usually referred to in terms of total harmonic
distortion (THD) which is the percentage of unwanted
harmonics of the drive signal present with the wanted
signal. Generally used to mean any unwanted change
introduced by the device under question.
Driver.
See transducer.
Dynamic Range.
The range between the quietest and the
loudest sounds a device can handle (often quoted in dB).
Efficiency.
The acoustic power delivered for a given
electrical input. Often expressed as decibels/watt/meter
(dB/w/m).
ESL.
The abbreviation for electrostatic loudspeaker.
Headroom.
The difference, in decibels, between the peak
and RMS levels in program material.
Hybrid.
A product created by the marriage of two different
technologies. Meant here as the combination of a
dynamic woofer with an electrostatic or ATF transducer.
Hz (Hertz).
Unit of frequency equivalent to the number of
cycles per second.
Imaging.
To make a representation or imitation of the
original sonic event.
Impedance. The total opposition offered by an electric
circuit to the flow of an alternating current of a single
frequency. It is a combination of resistance and reactance
and is measured in ohms. Remember that a speaker’s
impedance changes with frequency, it is not a constant
value.