Handbook for Sound Engineers

592 Chapter 16

with a PZMicrophone, tends to sound better than high
placement.
For classical recording, a more distant pickup is
necessary. A woodwind ensemble might be successfully
recorded using the techniques described previously for
string sections.

16.13.4.11 Electric Instruments

In this category are all instruments designed to be repro-
duced through amplifiers and loudspeakers. Electric
guitar; electric bass; various synthesizer, organ, and
other electronic keyboards; and acoustic instruments
with attached microphones or pickups designed for
amplification all fall into this category.
Generally, these instruments require microphone
placement with the associated amplifier/loudspeaker
combination. However, another technique is possible
and in many cases preferable—that is, the direct
recording of the instrument. Since most of these instru-
ments produce a microphone-level high-impedance
unbalanced output, all that is required in most cases is a
high-quality transformer, providing the match between
the instrument and the low-impedance balanced inputs
of most mixers. Various direct boxes are available, some
with active electronics to provide the required imped-
ance transformation. Almost all provide an output to
drive the instrument amplifier as well as the mixer, and
most have a ground switch to select the grounding
configuration with the least noise.
In many situations, the instrument and its amplifier
constitute a system. The amplifier, which may contain
loudspeakers or may be connected to a separate loud-
speaker system, may have a major effect on the sound
of the instrument. Taking a direct feed may result in a
totally unnatural sound.
Mic’ing the instrument amplifier may seem simple,
but often the cabinet contains several loudspeakers.
These may be identical loudspeakers or separate drivers
for various frequency ranges. A single close micro-
phone may not provide the proper balance. Even in
systems with identical loudspeakers, careless micro-
phone placement may result in phase discrepancies
producing a distant and/or colored sound. Two solutions
are practicable: either give the microphone a more
distant placement, far enough to be equidistant from all
the loudspeakers, or position it very close, to pick up
only one loudspeaker, Fig. 16-189.
Systems with multiple drivers for different frequency
ranges will have to be mic’ed from far enough away
that the various drivers are properly balanced. Although
it may be possible to mic the individual drivers and mix

them for the proper balance, this approach is more

prone to error.

Distant micing is often desired, especially for an

electric guitar. Naturally, the character of the room must

be appropriate.

Often a combination of the direct and mic’ed sound

is used. This combination can be effective, but the phase

relationship between the two sources will be arbitrary,

which can cause severe coloration of the sound. The

tonal balance will change unpredictably as the ratio of

direct and mic’ed sound changes. This change usually

precludes any gain riding of the individual inputs. A

phase reversal switch can sometimes be used to opti-

mize the gross phasing between the two inputs.

Instruments like synthesizers or other electronic

keyboards generally should be recorded directly. The

sound of these instruments is usually not augmented by

the addition of a musical instrument amplifier. There are

exceptions, however, and the choice of technique

depends on the effect desired—perhaps the limited

frequency response and soft distortion of a tube-type

amplifier is appropriate.

16.13.4.12 Percussion

The most common percussion instrument is the drum

kit. Other percussion instruments, such as congas,

tympani, handclaps, tambourines, timbales, wood

blocks, claves, or maracas, etc., require care in micing

due to the extreme levels encountered. It is not

uncommon to have levels of +10 dBm and more (open

circuit) on the output of a condenser microphone when

placed close to a percussion instrument or a piano.

Such levels can be very demanding of microphone

electronics, in the case of condenser microphones and

the associated mixer. The use of internal microphone

Figure 16-189. Mic’ing of electric instrument loudspeakers.

Microphone

0–12 inch

from grill cloth

Typical multiple

loudspeaker micing

A. Close microphone placement.

6 ft or more

Instrument amp

B. Distant microphone placement.