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reverberation, reverb
The sound remaining in a room after the
source of sound is stopped. It’s what you hear in
a large tiled room immediately after you’ve
clapped your hands. Reverberation and echo are
terms that can be used interchangeably, but in
audio parlance a distinction is usually made:
reverberation is considered to be a diffuse,
continuously smooth decay of sound, whereas
echo is a distinct, recognizable repetition of a
word, note, phrase or sound. Reverberation and
echo can be added in sound mixing by sending
the original sound to an electronic (or elec-
tronic/acoustic) system that mimics natural
reverberation, or worse. The added reverb is
returned to the blend through additional mixer
inputs. Highly reverberant rooms are called live;
rooms with very little reverberation are called
dead. A sound source without added reverb is
dry; one with reverb or echo added is wet.
RMS
An acronym for root mean square, a con-
ventional way to measure AC voltage and
audio signal voltage. Most AC voltmeters are
calibrated to read RMS volts. Other conven-
tions include average volts, peak volts and
peak-to-peak volts.
send
A term used to describe a secondary mix
and output of the input signals, typically
used for foldback monitors, headphone
monitors, or effects devices. Mackie mixers
call it an Aux Send.
shelving
A term used to describe the shape of an
equalizer’s frequency response. A shelving
equalizer’s response begins to rise (or fall) at
some frequency and continues to fall (or rise)
until it reaches the shelf frequency, at which
point the response curve flattens out and re-
mains flat to the limits of audibility. If you were
to graph the response, it would look like a shelf.
Or more like a shelf than a hiking boot. The EQ
controls on your stereo are usually shelving
equalizers. See also
peaking
and
dipping.
slap, slapback
A single-delay echo without any repeats.
Also see
echo.
solo
Italian for alone. In audio mixers, a solo
circuit allows the engineer to listen to indi-
vidual channels, buses or other circuits singly
or in combination with other soloed signals.
SR
An acronym for Sound Reinforcement,
which refers to a system of amplifying acoustic
and electronic sounds from a performance or
speech so that a large audience can hear
clearly. Or, in popular music, so that a large
audience can be excited, stunned or even
partially deafened by the tremendous amplifi-
cation. Means essentially the same thing as PA
(Public Address).
stereo
Believe it or not, stereo comes from a
Greek word that means solid. We use stereo
or stereophony to describe the illusion of a
continuous, spacious soundfield that is seem-
ingly spread around the listener by two or
more related audio signals. In practice, stereo
often is taken to simply mean two channels.
sweep EQ
An equalizer that allows you to “sweep” or
continuously vary the frequency of one or
more sections.
symmetrically balanced
See
balanced.
tinnitus
The ringing in the ears that is produced
with prolonged exposure to high volumes. A
sound in the ears, such as buzzing, ringing, or
whistling, caused by volume knob abuse!
trim
In audio mixers, the gain adjustment for the
first amplification stage of the mixer. The trim
control helps the mixer cope with the widely
varying range of input signals that come from
real-world sources. It is important to set the
trim control correctly; its setting determines
the overall noise performance in that channel
of the mixer. See
mic preamp.
