DG 1110.3.120
DESIGN GUIDE: MUSIC AND DRAMA CENTERS
JANUARY 1981
C H A P T E R 4: ELECTRONIC SYSTEMS
provide reverberation but to ensure that live
approaches related to loudspeaker locations.
sound arrives, establishing directional realism,
The most common arrangement employed by
closely followed by reinforcement sound. Crite-
touring companies using a Room without ade-
ria include low gain relative to stage and central
quate installed reinforcement is the temporary
sources, and required proximity to the affected
placement of speakers on each side of the pro-
audience to avoid echo perception at the front
scenium. Apart from. ease of set-up, there is
of the house. A slightly greater (+2 db) gain can
sometimes the advantage of reaching into un-
be obtained if under-balcony sound arrives about
derbalcony recesses. However, for the majority
15 milliseconds after the cluster sound.
of the audience, unnatural amplification will be
evident and in many instances distracting, due
The central cluster arrangement is the most likely
to directional conflicts between eyes and ears.
choice for Army facilities described in this Guide.
In extreme cases, sound from the more distant
In fact, it is probable only the large (1400 seat)
speaker will be heard as echo.
House will require a reinforcement system for
The most common installed system utilizes a
multi-use programming, to increase speech in-
telligibility for drama presentation and enable
central loudspeaker cluster directly over the
popular entertainers, using electronics as part of
proscenium. This very simply eliminates split
their art form, to effectively function in the space.
system problems by positioning the speakers in
a complementary spatial and temporal relation-
The main components would be a central cluster
ship to the onstage source; the sound arrives
three-way loudspeaker system with separate
from the same direction and at the same time.
low, mid, and high end speaker components.
The only exceptional circumstances would be
Each of these components should be amplified
dialogue across a very wide proscenium, down
separately and balanced with electronic cross-
a very deep stage, or in a Thrust or Surround
over networks. The design of such a system re-
arrangement. In other words, it assumes a dom-
quires an experienced professional.
inant central focus. Its only physical disadvan-
tage may be the difficulty of reaching under deep
While this preferred system utilizes a limited
balconies from an especially high proscenium
number of loudspeaker outputs, it requires a
position.
multitude of input microphone receptacles in the
stage area and current practice is to provide a
A variation of the central cluster scheme re-
40-pair shielded cable from the stage to the con-
sponds to the first exception by locating three
trol location in the house and the main control
to five clusters across the width of the proscen-
booth.
ium, with corresponding microphone inputs so
that apparent sound direction moves with its
It is essential that the sound reinforcement con-
source. Either the microphones or the wireless
sole be operated from a position in the house.
receivers (if used) must have directional qualities
It is impossible for an operator to achieve good
while the speakers do not, to avoid differential
balance of either speech or music programs
delays caused by source distance across the
when operating the system in a closed booth, or
stage. Alternatively, fixed omnidirectional micro-
in a booth having an operable window. For this
phones may incorporate preset time-delay feeds
reason, the tie lines are split at the stage with
to each speaker, the longest to the most distant
one set going to an in-house console location,
speaker, along with a scaled level adjustment.
and another set going back to the control room.
Often only the central cluster is used for speech
Since it is necessary to move the console from
presentation, and the others turned on for large
the control room to the house position fre-
choral or orchestral groups, stereophonic ef-
quently, it might very well be advisable to pur-
fects, or high level amplification (rock or popular
chase standard commercial reinforcement con-
music) that would overpower and distort the nor-
soles in modular sections of 8 to 12 input
mal central cluster elements.
channels each. Three 8-input channel boards can
be plugged together to form a 24-input channel
Finally, carefully designed directional side clus-
mixer, a reasonably sophisticated device for a
ters or a distributed loudspeaker system may be
1400-seat house.
installed supplemental to the central system, for
deep under-balcony spaces or for unusually
Please bear in mind that if the 1400-seat house
"dead" or uneven Rooms encountered in found
has high drama use, additional output channels
space conversions. The distributed system al-
and speaker delegation switches will be re-
ways incorporates time-delay processing, not to
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