Theatre Design & Technology - Feb 1972 - 17

normal work position, to hear a production or rehearsal taking place on the stage, and should permit the stage manager to interrupt the monitoring
signal and page specific members of the production staff. Generally, monitoring with paging override should be provided to the artists' and groups'
dressing rooms, lounges, Green Room, scenery
and costume shops, and stage door. Monitoring
only should be provided for the house manager's
office, the box office, a possible VIP room, and
the light and projection booths. Specific theatre requirements should, of course, add to these two
lists.

Iy added. Such systems fall into two categories:
(1) unattended, merely switched on and off, as in
London's Royal Festival Hall; or (2) operated, as at
the University of Western Michigan's auditorium in
Kalamazoo. Such systems should rarely be used
during dialogue; the added reverberation and return
of sound energy from the rear of the theatre wi II
reduce speech intelligibility and clarity. Instead,
such a system may be used with an orchestra (in
the pit or on the stage), a chorus, organ, popular
singers, folk singers, and rock bands. Basically,
such a system can make an auditorium optimumly
designed for the spoken word sound like a concert
hall.

System and Equipment
Monitoring and paging systems should not require a sound system operator. The stage manager
should be able to page at the push of a button,
with all level controls preset; the monitoring system should be left alone, once adjusted. Therefore,
all mixer-preamplifiers, power amplifiers, and relays should be rack-mounted in the sound control
room shared either with the effects or the reinforcement system.
Loudspeaker coverage is usually provided by
built-in eight-inch cone-type direct radiator loudspeakers built into walls and ceilings of the rooms
covered. Individual loudspeaker-line level controls
may be provided for specific dressing rooms or
other spaces; often these controls are bypassed
for the paging function. Bypassing the controls requires four wires to the specific room, instead of
two.
Microphone pick-up for monitoring usually requires one or two suspended microphones in front
of the proscenium; these may be shared with the
archival recording system. Or a feed may be derived from the reinforcement system control console. The stage manager's paging microphone
should be a push-to-talk close-talking microphone.
Selective paging of specific rooms requires more
controls for the stage manager to operate, increases cost and complexity of the paging system,
and is not required by most theatres.

* SURROUND AND ELECTRONIC
REVERBERATION SYSTEMS
Purpose
Surround and electronic reverberation systems
are intended to complement the specific acoustical
environment of a particular theatre to make that
theatre sound more reverberant, live, and possibly
larger than indicated to the listener by the natural
acoustics alone, or with a reinforcement system on-

c::::§lJ THEATER DESIGN AND TECHNOLOGY

FEBRUARY. 1972

Alternate Basic System
The fixed, non-operated system at London's
Royal Festival Hall has been defined as an "assisted resonance" system. It uses over a hundred
microphones, mounted in resonant chambers in the
hall ceiling, each feeding an amplifier that drives
one of over a hundred loudspeakers. The design
and installation were carefully worked out to complement the standing wave pattern of sound in the
hall. Each channel handl es only a limited bandwidth
a few hertz (cycles-per-second) wide; together the
entire system is effective in the 56-700 Hz.
range. Such a system should logically be switched
off for dialogue activities and switched on for
music, this would be the entire extent of operation.
The system at the University of Western Michigan represents an alternate approach. Stage suspended microphones or reinforcement system microphones feed a control console that combi nes the
functions of controlling reinforcement and surround
and reverberation. This signal is then routed
through a delay system (tape-loop in this case)
and a reverberant chamber before distribution to
twelve fifteen-inch full-range loudspeakers in the
main ceiling and additional eight-inch loudspeakers
in the main ceiling and additional eight-inch loudspeakers in the balcony soffit. The system is used
for a wide variety of popular music events and occasionally for the pit orchestra in a musical comedy
production, as well as orchestral concerts. The
amount of added reverberant energy is selected by
the sound system operator for the particular event.
Controls for the overall loudness ofthe reverberation and surround system must be well matched to
the live sources and reinforced sound in the theatre. For adding liveness and reverberation to a rock
band, for example, Iiterally thousands of watts of
amplification may be required, particularly if the
theatre surround loudspeakers are low-efficiency
direct radiator or column loudspeakers.

Table of Contents for the Digital Edition of Theatre Design & Technology - Feb 1972