Handbook for Sound Engineers

Sound System Design 1265

34.3.2.9.2 Commercial Computer Software Design
Tools

As personal computers grew in power, the man-
ual/graphical design tools were ported to the PC.
Among the early computer programs for cluster design
were JBL’s CADP, Bose Modeler, Electro-Voice/Altec
AcoustaCADD, Thomas McCarthy’s Umbulus, and
John Prohs PHD Program.

The cost of maintaining these programs and
compiling the necessary database of loudspeakers is
high and two commercial software programs have come
to dominate the field. The first, EASE, was developed
by consultant Dr. Wolfgang Anhert, and is distributed
by Renkus-Heinz, Fig. 34-21. The other, Modeler, is a
proprietary program developed and distributed by Bose.
EASE runs on a Windows-based PC. Modeler runs on
an Apple Macintosh or a Windows-based PC.

Modeler, while a very capable program, is only
usable with Bose loudspeakers. Check with the Bose
Corporation for updates to this policy. As a result,
EASE, which can be used with any manufacturer’s
loudspeakers, is preferred by most designers. Either
program has a considerable learning curve and designers
must attend one of the available training classes.

Before designing a cluster with either program, the
user must enter a detailed room description in three
dimensions. This means the user must have accurate

and detailed room dimensions and should be familiar

with computer aided drafting methods. The programs

will import properly prepared computer aided drafting

files, such as those produced with AutoCAD.

To use a chosen loudspeaker in either program, the

loudspeaker manufacturer must provide compatible data

files. Most major loudspeaker manufacturers provide

these files but data files for certain loudspeaker models

may not be available.

The requirement to enter detailed room data and the

lack of availability of some loudspeaker data are limita-

tions that may inhibit a designer from using EASE or

Modeler on certain projects. However, the power and

versatility of these programs are very high and most

designers will want to utilize one of these programs for

most projects. Chapters 9 and 35 provide additional

details about computer room modeling and auralization.

34.3.2.9.3 Other Software Tools

Additional software tools are available for specialized

applications. As an example, Syn-Aud-Con offers a

multifunction spreadsheet that calculates many of the

equations in this chapter and provides other useful func-

tions.

34.3.2.10 Designing the Complex Cluster

Although programs like EASE and Modeler handle

complex clusters well, it’s important for the designer to

understand the difficulties behind such a design. In con-

cept, the design of a multiloudspeaker central cluster in

a room with complex geometry is no different from the

simple rectangular room design discussed in Section

34.3.2. In practice, the complex cluster shown in Fig.

34-22 presents a set of new difficulties.

First, the complex cluster is most often designed for

a large public facility. In practically every such situa-

tion, the budget will be tight, leaving no room for errors

in design. It is simply not economically possible to

redesign a large cluster after it has been installed.

Second, many of the approximations used in the

simple cluster design method are too gross to be used in

the design of a complex cluster. For example, the

approximations used for the value of N in the Alcons

equation need to be refined for a complex cluster design.

Here, based on the four questions, is a primarily

qualitative explanation of some of the refinements

needed for the design of a complex cluster. Some quan-

titative explanations are given, but a full, quantitative

analysis of the complex cluster is beyond the scope of

this discussion. EASE or Modeler will greatly help in

Figure 34-21. EASE. Courtesy Renkus-Heinz.