Mackie SR24•4 Owner's Manual page 49

ated by bouncing electrons in the transistor
junctions. The lower the noise floor and the
higher the headroom, the more usable dy-
namic range a system has.
pan, pan pot
Short for panoramic potentiometer. A pan
pot is used to position (or even move back
and forth) a monaural sound source in a ste-
reo mixing field by adjusting the source's
volume between the left and right channels.
Our brains sense stereo position by hearing
this difference in loudness when the sound
strikes each ear, and also take into account
time delay, spectrum, ambient reverberation
and other cues.
parametric EQ
A "fully" parametric EQ is an extremely
powerful equalizer which allows smooth, con-
tinuous control of each of the three primary
EQ parameters (frequency, gain, and band-
width) in each section independently. "Semi"
parametric EQs allow control of fewer param-
eters, usually frequency and gain, i.e., they
have a fixed bandwidth, but variable center
frequency and gain.
peaking
Is the opposite of dipping, of course. A
peak is an EQ curve which looks like a hill, or
a peak. Peaking with an equalizer amplifies a
band of frequencies.
PFL
An acronym for Pre Fade Listen, or PRE
FADER on the SR24•4. Broadcasters would
call it cueing. Sound folks call it being able to
solo a channel with the fader down.
phantom power
A system of providing electrical power for
condenser microphones (and some electronic
pickup devices) from the sound mixer. The sys-
tem is called phantom because the power is
carried on standard microphone audio wiring in
a way which is "invisible" to ordinary dynamic
microphones. Mackie mixers use standard +48
volt DC power, switchable on or off. Most quality
condenser microphones are designed to use +48
VDC phantom power. Check with the
manufacturer's recommendations.
Generally, phantom power is safe to use with
non-condenser microphones as well, especially
dynamic microphones. However, unbalanced
microphones and equipment, some electronic
equipment (such as some wireless microphone
receivers) and some ribbon microphones can
short out the phantom power and can be
severely damaged. Check the manufacturer's
recommendations and be careful!
phasing
A delay effect, where the original signal is
mixed with a short (0 to 10 msec) delay. The
time of the delay is slowly varied, and the
combination of the two signals results in a
dramatic moving comb-filter effect. Phasing
is sometimes imitated by sweeping a comb-
filter EQ across a signal. A comb filter can be
found in your back pocket.
phone jack
Ever see those old telephone switchboards
with hundreds of jacks and patch cords and
plugs? Those are phone jacks and plugs, now
used widely with musical instruments and in
audio equipment. A phone jack is the female
connector, and we use them in 1/4" two-
conductor (TS) and three-conductor
(TRS) versions.
phone plug
The male counterpart to the phone jack,
right above.
phono jack
See RCA phono jack.
phono plug
See RCA phono plug.
post-fader
A term used to describe an aux send
(usually) that is connected so that it is af-
fected by the setting of the associated
channel fader. Sends connected this way are
typically (but not always) used for effects.
See pre-fader.
pot, potentiometer
In electronics, a variable resistor, which
varies the potential, or voltage. In audio, any
rotary or slide control.
pre-fader
A term used to describe an aux send
(usually) that is connected so that it is not af-
fected by the setting of the associated channel
fader. Sends connected this way are typically
(but not always) used for monitors
(foldback). See post-fader.
proximity effect
The property of many directional micro-
phones to accentuate their bass response when
the source-to-mic distance is small, typically
three inches or less. Singers generally like this
effect, even more than singing in the shower.
Appendices
47