582 Chapter 16
roll off the low or high end, increase the 3–5 kHz articu-
lation region, or reverse polarity. These units normally
have standard input and output male and female XLR or
¼ inch phone plug connectors. Attenuators are also
available to be installed between the capacitor capsule
and the condenser microphone electronics to eliminate
overload from high-level sources.
16.13 Microphone Techniques
Micing is more of an art than a science. Therefore there
is no one way to position a microphone for good
recording. It is subjective and at the control of the engi-
neer. The discussions of microphone placement in the
following sections are only suggestions or the ideas of
one engineer.
The quality of the reproduction can be greatly influ-
enced by the position of a microphone in relation to the
sound source. When only one microphone and one
sound source are involved, this positioning is fairly
straightforward: the closer the microphone, the more the
direct sound will dominate over the reverberant sound.
Except in an anechoic chamber, there will always be a
certain amount of reflected sound present in the micro-
phone output. This results from sound bouncing off
boundaries such as the floor, ceiling, walls, and objects
of significant proportions located in the area of the
microphone. At a certain distance from the sound
source, the amount of reflected sound will exceed the
amount of the direct sound. The microphone is then said
to be in the reverberant, or far, field. The effect is to
make the acoustic environment (usually a room) more
evident to the listener than would be the case with close
micing (microphone in the near field).
The proper position of the microphone depends on
the effect desired. Close micing produces a highly
present, up-front sound, with little of the acoustic envi-
ronment evident, whereas distant micing produces a
more spacious sound with the room characteristics
becoming very obvious. A close microphone position
may not accurately reproduce the sound of the source,
and equalization may be required to achieve a sound
similar to the natural sound. If the room acoustics are
not suited to the sound reproduction desired, a distant
microphone position may produce an unpleasant or
unintelligible result. The correct choice requires the
engineer to choose the appropriate microphone position
for the sound desired. A microphone placed an inch
from a snare drum will produce an up-front,
bigger-than-life sound, which could be appropriate for a
modern rock recording but might be totally inappro-
priate for a jazz or big band recording. Distant micing of
the snare drum could produce a powerful effect, in any
kind of music, since the contribution of a good room
might be important to the music.
It is rare that there is just one microphone and one
sound source. Modern recording often requires the use
of multiple microphones. Microphone placement then
becomes more complicated, because as the microphone
is moved farther from its intended source, more of the
other sources will be picked up as well. No instrument
is a point source, and there are different characteristic
sounds emanating from various places on the instrument
(i.e., a flute has vastly different sounds coming from the
open end, the body of the flute, or the mouthpiece).
Most instruments have complex directional characteris-
tics, that vary from note to note. Even instruments of the
same make and model can sound quite different from
one another.
Whenever there is more than one microphone
receiving sound from a single source, a problem of time
and phase differences can become audible. This
problem can have a major effect on the frequency
response, presence, and clarity of the recording. The
result for spaced microphones can be a comb filter
effect, which will tend to reduce presence, upset the
natural balance of various notes and overtones, and
disturb localization of the source. In an extreme case,
certain notes may be attenuated to inaudibility. In prac-
tice, the contribution of room reflections, pickup by
other microphones, and intrinsic instrument imbalances
may mask many of these effects.
Multitrack recording generally requires the engineer
to isolate instruments so that only the intended source is
recorded on each track. Sometimes this is simple
because the track is being overdubbed and only that one
instrument is in the studio. At the other extreme, an
entire ensemble may be playing at once, yet the situa-
tion may require that all instruments be totally isolated
on the tape tracks so that they can be individually
mixed, processed, or even replaced with no effect on the
other instruments. The latter requires very careful
microphone choice and placement and/or the use of
isolation booths for some troublesome instruments. If
the musical balance is good in the room, the job is fairly
simple. But if there are obviously incompatible instru-
ments playing simultaneously (e.g., heavy drums versus
a finger-picked acoustic guitar), isolation solely through
microphone technique becomes next to impossible.16.13.1 Stereo Micing TechniquesModern recording practice often employs multiple
microphones, each feeding a separate track of a multi-