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Digital Audio
Digital Audio is a sound signal that has been
converted into numerical values. Digital sound
can be transmitted through multiple channels.
Analog sound can only be transmitted through
two channels.
Duplex (half/full)
Full duplex is the ability to send and receive
data simultaneously. Duplex is synonymous
with full duplex. Example: when a modem
operates in full-duplex mode, it can transmit
data in two directions simultaneously. In
half-duplex mode it can transmit data in two
directions, but not simultaneously.
E
Encryption key
An encryption key is an alphanumeric series
that enables data to be encrypted and then
decrypted so it can be safely shared among
members of a network.
F
Frequency
The property or condition of occurring at
frequent intervals. In sound, this simply refers
to the regular occurrence of compression and
rarification of air that we experience as sound.
Frequency Response
Is the range of frequencies that a speaker
reproduces, lowest frequency to the highest.
While the optimal normal is 20-20,000 Hz
(Hertz), the range of human hearing for
individuals is often much more restricted.
A good full-range speaker system however,
reproduces as much of this range as possible
to cover all variations. Individual drivers are
limited to reproduce only that part of the
spectrum for which they were made, so their
response is limited, but still a necessary point
to consider when designing a complete sound
system.
being played, and then downloads the title,
artist, and track list.
Coaxial
A single copper conductor, surrounded with
a layer of insulation, covered by a surrounding
copper shield and finally, an insulating jacket.
An unbalanced transmission line with constant
impedance. In audio, this type is commonly
used for low level, line signals terminated in
RCA connectors.
Compression
In audio terms, this is a process of temporarily
or permanently reducing audio data for more
efficient storage or transmission. A temporary
reduction in file size is called ‘non-lossy’
compression, and no information is lost. A
permanent reduction in file size (such as with
MP3 files) is called ‘lossy’ compression, and
involves discarding unnecessary information
which is irretrievably lost.
D
DC (direct current)
Direct current or continuous current is
the constant flow of electric charge. This is
typically in a conductor such as a wire. In
direct current, the electric charges flow in
the same direction, distinguishing it from AC
(alternating current).
Decibel (dB)
A unit of measure used to express relative
difference in power or intensity of sound.
DHCP
DHCP stands for Dynamic Host Configuration
Protocol. It is a protocol for assigning dynamic
IP addresses to devices on a network.
Digital
A method to encode information using a
binary code of 0s and 1s. Many wireless
phones and networks use digital technology.
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