Theatre Design & Technology - Winter 2005 - 16

View of the R. Fraser Elliott Hall in the
Four Seasons Centre for the Performing
Arts. Courtesy Diamond and Schmitt
Architects. Rendering by Cicada Design.

Centre over each season, each bringing in two
or three productions at a time for a several
weeks' use of the building.
The COC currently runs thirty-six performances per year: six productions play six performances each. These are run in three
periods over the season, two production playing in rep at a time. Even in the 3,200-seat
Hummingbird Centre, they achieved a box office of ninety-five percent last season, so moving to a 2,000-seat venue will require an
immediate increase to fifty-four performances.
Over the next few years they plan to increase
this to seventy performances with longer runs
in three-production repertory. The NBOC currently produces sixty-four performances per
season, and this will immediately increase to
ninety-one in the Four Seasons Centre. The
companies will continue to use their existing
administrative, rehearsal and support facilities, both of which are within a mile or so of
the new building.
The design of the performance space, R.
Fraser Elliott Hall, is based on the traditional
European opera house, with four tiers of wraparound balconies above the relatively compact
orchestra seating. The design of the auditorium has been driven by a desire to create the
best possible acoustical environment for enjoying the performance of opera and ballet.
Apart from the greater visual and acoustical intimacy, the multi-tiered design allows for a
more compact footprint, which is essential
given the Centre's downtown site.
Before even contemplating the design of
the auditorium, the site itself presents serious
acoustical challenges. Located at a busy downtown intersection, the constant din of traffic
continues around the clock, and a row of five
hospitals a few blocks north ensures a regular
parade of sirens. For low-frequency vibrations,
the only thing worse than the streetcar traffic

along the north wall of the site is the subway
line immediately to the west. Substantial
acoustical isolation was required in the design
of the hall.
To reduce internal noise, the there will be
a convection-based HVAC system, using a large
volume of air moving at low speed from massive plenums below the orchestra seating and
balconies through outlets in the pedestal of every fixed seat. This system has proven to be
very effective in reducing ambient noise levels
in concert and opera halls in Europe, and has
become more popular in North America in the
past decade. In Canada, we have found that the
use of this system requires efficient and mandatory coat-check facilities: winter coats
draped over seats can seriously disrupt the airflow through the seat pedestals.
Acoustics and sightlines have driven the
design of the auditorium, and a series of computer modeling tools have been used to refine
the design, and minimize the conflicts-or at
least reach the optimum compromise-between the architect, the acoustician, and the
lighting designers.
Three-dimensional CADD and rendering
software are now well-established tools for the
architect: some of these renderings accompany this article. Once Diamond and Schmitt
had produced the design for the auditorium,
this design went to theatre consultants Fisher
Dachs. They have developed a program that
can render the view towards the stage from
each seat in the auditorium, and this was used
to verify sightlines and adjust seating positions.
The acoustical consultant, Sound Space
Design Ltd., has developed modelling software to render an acoustical model of a
space. Using a digitized model of the auditorium, sounds with different combinations of
frequencies are situated at various places upon
the virtual stage and fired into the auditorium.

When these virtual sounds hit virtual seats and
surfaces in the auditorium, some frequencies
are reflected, while others are absorbed. The
degree of reflection or absorption is shown in
a range of colored areas in the model. It
sounds a bit like a game of virtual paintball,
and the staff at the COC have nicknamed the
program "Sound Splat." As more and more virtual sounds are fired, the splats start to build a
picture of the properties of the hall and highlight areas that need modification. Shapes and
surfaces are then adjusted to fine-tune the
characteristics of the auditorium.
In this manner, the shape of the auditorium has been sculpted to refine its acoustical
properties, and this sculpting begins at the
plaster line. Plan drawings of the proscenium
arch itself reveal a progressive curve rather
than the typical right-angled return. This process has become particularly interesting in the
ceiling. The center section drawing also shows
a series of progressive curves starting at the
proscenium, as opposed to the traditional
sounding board.
The interplay between acoustic and lighting requirements has been particularly interesting. In all too many theatres, architects and
acousticians have created their ideal ceilings
with little regard for required lighting positions. Sooner or later, slots are cut to provide
the required hanging positions, and the acoustical quality is compromised.
In this case, while the acousticians were
virtually modelling the ceiling in their software, the staff of the opera started modelling
lighting positions in WYSIWYG, the popular
lighting design and rendering program created
by Cast Lighting in Toronto. With the assistance
of Cast president Gil Densham and Andrew
Read, a WYSIWYG expert with Pan Tilt Studios,
the auditorium was imported into the program, including the planned FOH cove and
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