46 AUDITORIA 2019 VOLUME ONE
“Because the added reflections are designed in
such a way that they do not affect the perceived
location of the instruments, the resulting
orchestra sound is as clear and transparent
as if it was an entirely uncovered pit.”
The second part of the solution was
fundamentally new. Orchestral arrangements
where the orchestra was able to play in a standard
formation – with the string sections surrounding
the conductor and the woodwinds positioned in
the center of the orchestra – showed a much
better acoustic impression. To make this
orchestra arrangement possible for opera or
ballet performances with a larger orchestration,
the pit needed flexible absorption. In addition
to a fixed diffuse and partly absorbent new
cladding in the pit, mobile absorber elements
were designed in collaboration with Scott Carver
Architects to support an array of orchestral
arrangements and increase the absorption in the
pit where necessary. This helped to reduce the
sound levels in the pit.
“To provide a more supportive acoustical
situation for the musicians, a quite exceptional
extension of the acoustic enhancement system
was used, creating a sound field that is naturally
impossible to achieve with the given pit volume,”
says Engel. “This setup used very weak early
reflections together with the reverberation tail
of a large rehearsal hall. With this configuration,
the musicians experience the room acoustics
helpfully, supporting them without any adverse
increase in loudness that a natural sound field
would inevitably cause.”
Before starting the construction work, this
solution was tested with a temporary installation
on-site in two performance blocks with Opera
Australia and the Australian Ballet. The results
were then revealed at the reopening of the Joan
Sutherland Theatre on New Year’s Eve 2017.
“It was a memorable experience when the
acoustical results exceeded all expectations,
proving that innovative solutions can truly
sound like a miracle,” says Engel. n
famous shells in place are located at the wall
between the pit and the audience. Investigations
on these tie beams revealed that relocating
them would require a much longer downtime.
Consequently, an extraordinary and innovative
approach needed to be developed.
To improve the acoustics in the auditorium,
an acoustic enhancement system was suggested.
This would improve the acoustics for the
audience and orchestra without having to
change the footprint of the orchestra pit.
One task for the acoustic enhancement
system is supporting the instruments located
in the covered part of the orchestra pit with
additional reflections. “These reflections
simulate typical proscenium reflections;
therefore, the projection of the instruments
at various positions in the pit into the audience
is much more balanced,” explains Engel.
Above: The acoustic
enhancement system enables
without impacting the hall’s
seat capacity, which is
opened in 1973
SYDNEY OPERA HOUSE RENEWAL
The renewal of the Sydney Opera House is a massive,
multistage project with a total projected cost of A$273m
(US$192m), the majority funded by the NSW Government.
The first stage included upgrades to the Joan Sutherland
Theatre focusing on the acoustics, accessibility and safety,
including replacing technical systems and equipment.
This was completed in December 2017.
Similar work will be completed in the venue’s Concert Hall.
The acoustics, stage and backstage areas, theater systems
and accessibility will be addressed.
The project also includes upgrades to the building’s entry
and foyer areas, plus the creation of two completely new
spaces – a Creative Learning Centre for young people,
and a new function center.