Mackie SR24•4 Owner's Manual page 45

condenser usually refers to a design of micro-
phone which uses a capacitor as the sound
pickup element. Condenser microphones re-
quire electrical power to run internal amplifiers
and maintain an electrical charge on the capaci-
tor. Thy are typically powered by internal
batteries or "phantom power" supplied by an ex-
ternal source, such as a mixing console.
console
A term for a sound mixer, usually a large
desk-like mixer.
cueing
In broadcast, stage and post-production
work, to "cue up" a sound source (a record, a
sound effect on a CD, a song on a tape)
means to get it ready for playback by making
sure you are in the right position on the "cue,"
making sure the level and EQ are all set prop-
erly. This requires a special monitoring circuit
which only the mixing engineer hears and
does not go out on the air or to the main mix-
ing buses. This "cueing" circuit is the same as
pre-fader (PFL) solo on a Mackie mixer, and
often the terms are interchangeable.
dB
See decibel
dBm
A unit of measurement of audio signal level in
an electrical circuit, expressed in decibels refer-
enced to 1 milliwatt. The "m" in dBm stands for
"milliwatt." In a circuit with an impedance of 600
ohms, this reference (0dBm) corresponds to a
signal voltage of 0.775 VRMS (because 0.775 V
across 600 ohms equals 1mw).
dBu
A unit of measurement of audio signal level
in an electrical circuit, expressed in decibels
referenced to 0.775 VRMS into any imped-
ance. Commonly used to describe signal levels
within a modern audio system.
dBv
A unit of measurement equal to the dBu but
no longer in use. It was too easy to confuse a
dBv with a dBV, to which it is not equivalent.
dBV
A unit of measurement of audio signal level
in an electrical circuit, expressed in decibels
referenced to 1 VRMS across any impedance.
Commonly used to describe signal levels in
consumer equipment. To convert dBV to dBu,
add 2.2dB.
decibel (dB)
The dB is a ratio of quantities measured in
similar terms using a logarithmic scale. Many
audio system parameters measure over such a
large range of values that the dB is used to sim-
plify the numbers. A ratio of 1000V:1V=60dB.
When one of the terms in the ratio is an agreed
upon standard value such as 0.775V, 1V or
1mw, the ratio becomes an absolute value, i.e.,
+4dBu, –10dBV or 0dBm.
delay
In sound work, delay usually refers to an
electronic circuit or effects unit whose pur-
pose it is to delay the audio signal for some
short period of time. Delay can refer to one
short repeat, a series of repeats or the com-
plex interactions of delay used in chorusing or
reverb. When delayed signals are mixed back
with the original sound, a great number of
audio effects can be generated, including
phasing and flanging, doubling, Haas-effect
positioning, slap or slapback, echo, regenera-
tive echo, chorusing and hall-like
reverberation. Signal time delay is central to
many audio effects units.
detent
A point of extra physical resistance (a click-
stop) in the travel of a knob or slide control,
used in Mackie mixers to indicate unity gain.
dipping
Is the opposite of peaking, of course. A dip
is an EQ curve which looks like a valley, or a
dip. Dipping with an equalizer reduces a band
of frequencies. (See guacamole.)
doubling
A delay effect, where the original signal is
mixed with a medium (20 to 50 msec) delay.
When used carefully, this effect can simulate
double-tracking (recording a voice or instru-
ment twice).
dry
Usually means without reverberation, or
without some other applied effect like delay
or chorusing. Dry is not wet, i.e. totally
unaffected.
dynamic
In sound work, dynamic refers to class of
microphones which generate electrical signals
by the movement of a coil in a magnetic field.
Dynamic microphones are rugged, relatively
inexpensive, are capable of very good perfor-
mance and do not require external powering.
dynamic range
The range between the maximum and
minimum sound levels that a sound system
can handle. It is usually expressed in decibels
as the difference between the level at peak
clipping and the level of the noise floor.
Appendices
43