Speaker Systems for Background Music and Paging
page 2
Electro-Voice Installed Sound Technical Guide
with patrons. Will the person issuing pages be sitting under or near a
speaker? If so, then consider equalization, or a separate muting circuit, to
avoid feedback. Is light-switch height a comfortable location for zone
volume controls, or does the user have another preference? Getting this kind
of information at the beginning will help to avoid confusion and delays at
the installation stage.
Just as important as the human factors are the construction details of the
site. How are the walls and ceilings constructed? What kinds of mounting
surfaces will be encountered? Is the drop ceiling a lay-in type, or tongue-
and-groove? Where must cabling be routed, and how accessible are those
spaces? Do partition walls or bearing members extend above the drop
ceiling, where they may obstruct cable runs? Is conduit or plenum cable
required? All of these factors directly affect the price quote and the actual
task of installation.
Defining The System
Upon completion of a thorough site survey, the system may be specified and
quoted. The sales engineer also usually generates the design and quote, often
at the same time as the site survey. Success at this stage depends experience
and product knowledge.
To avoid ambiguity and confusion at the installation stage, the specification
needs to be as explicit as possible. Of course, it should enumerate all of the
equipment proposed to do the job, and should include both a block
diagram and an accurate floor plan with annotations regarding construction.
In addition, it should provide details such as local volume control locations
and height, the desired location for amp racks, and even names of the
employees who are expected to use the system. To forestall disputes and
clarify responsibility if changes are required during or after installation, the
customer should be asked to sign a written agreement governing the
specification.
Many contracting companies simply communicate the sales engineer’s
design directly to their installation department, who are charged with
putting the system in and making it work. There are potential problems
with this approach. For example, the salesman’s natural tendency is to over-
design and oversell when he can. If the client is amenable, the result can be
an excessively complicated (and problematic) system. Moreover, it is easy to
make mistakes in the flush of a sale, and these may be compounded when
the system goes in.
©2002 Telex Communications, Inc.
