| The Music Scene Vol. 1 No. 1 | | | The Artec of Sound by Wah Keung Chan Tuesday, October 22, 2002
The common denominator in the finest halls is the acoustic
design of Artec Consultants.
Everyone who attends a live performance experiences the
thrill of the sound of music launched from the stage and reflected in the hall.
Depending on the acoustics of the hall, the result can be good or great. Several
major projects over the course of the next four years will see concert-going
become a better listening experience--because good natural acoustics are core to
the designs.
Poor acoustics were the inspiration for the renovations
undertaken at Toronto''s Roy Thomson Hall over the last six months. Musicians and
audiences alike have complained since its opening 20 years ago of the dead
acoustics from the stage and inconsistent experiences according to the seats.
Damian Doria, President of Artec Consultants, the acousticians for the project,
blames the huge volume of space of the original design and the openings to the
attic where sound is lost. When the hall officially reopens with a gala on
September 21, among the solutions in the $20 million project is a series of 23
wooden bulkheads at the top of the hall that effectively reduces the volume of
the hall by 13.5% (see side bar).
The announcement of the new Montreal Symphony concert hall
and the new Canadian Opera Company Opera House in Toronto (the Four Seasons
Centre for the Performing Arts) within three months of each other this spring
has reinvigorated the prospect for excellent music making in both cities. Both
houses should be ready in 2005. At the same time, new halls or studios are being
planned at the Royal Conservatory of Music and McGill''s Faculty of
Music.
A Canadian trend
Canada already has a tradition of acoustically good halls:
the Winspear in Edmonton, the Chan Centre in Vancouver, the Jack Singer Concert
Hall in Calgary, the Weston Recital Hall in the Toronto Centre for the Arts,
Domaine Forget in Charlevoix, all built in the last 20 years. The common
denominator in all of these halls is the acoustic design of Artec Consultants.
And not coincidentally, Artec are already the designated acousticians for the
RCM and McGill projects, and they have submitted their candidature for the MSO
hall as well. Artec did the acoustic design of the original COC opera house plan
years ago, and the firm is in the running again this time.
Artec''s track record has everything to do with their proven
product. "It is very important for opera companies, symphonies, and government
agencies that are searching for theatre planning consultants that somehow you
have some very good finished projects not too far from them," says 78-year-old
Artec founder, CEO and chief acoustician Russell Johnson, whom Norman Lebrecht
in La Scena Musicale Online called the one man on earth who can give
conductors the perfect sound. "When our opera houses open in Singapore and S?o
Paulo, Brazil, we should increase our projects in those parts of the world. I
started to work in Canada with the firm ARCOP in Montreal in 1955 and so we got
started in Canada many decades ago and this gradually led to more and more
projects."
Acoustic secrets
What are Artec''s secrets of success? According to Doria,
"Artec has focused throughout its history in making rooms extremely quiet. For a
long time we''ve been using the threshold of hearing as a goal in background
noise level in the hall, so that a person can''t hear anything but that which is
created in the performance. Engineers didn''t want to believe that it is possible
to achieve something like that--most air conditioning and lighting systems
create plenty of noise. Now with microphones, with the CD in the 1980s, we were
faced with a situation where in order to have a recording without tremendous
amounts of noise on it, you have to have a quiet room to begin with. Before that
time, the recording and broadcast people didn''t really care about some noise in
their rooms, the quietest studio has quite a bit of noise. Back in the 1970s and
80s, Artec was already insisting on silent rooms long before anyone in broadcast
and recording thought it was important, to allow the performers to create an
intimate bond between themselves and the audience and to maximize the dynamic
range in the room so as to be able to play pianissimo and be heard
clearly."
Artec continues to push the envelope of silence: the McGill
recording studio is slated to be the quietest in the world.
Many of Artec''s successful halls are rectangular in shape.
Explains Doria, "The rectangle or shoebox allows you to simultaneously achieve
the sufficient amount of clarity with the long reverberation time. If you shape
the hall based on the rectangle, you are creating a situation where there is
strong lateral energy coming from the side walls which both create an enveloping
sound and reinforce the clarity of sound. The sound that reaches the listener in
the first 70-80 milliseconds reinforces, in the way you hear
psycho-acoustically, the direct sound you are hearing from the performance in a
way that adds a great amount of clarity. And if you make a fairly tall shoebox
like many of our halls are, the sound that ends up at the top of the room
filters back into the room later and gives you the long reverberence that many
types of music look for. There are some reasonably successful alternatives, but
they often have elements that are comparable to shoeboxes: hybrid forms that
have a lot of narrow parallel surfaces, a lot of reflective ledges that are
close to the audience. If the idea is to get the best acoustics with the best
investment, then a shoebox is a very good place to start."
Planning an opera house
While Artec would not talk specifically about the COC
project, they readily shared their experiences of opera houses. "The great
houses of the past centuries were very tight volumes. The reason why they could
fit enough into those spaces is because they didn''t mind cramming people very
close together. Today, we are concerned about how to get people out of a fire,
meaning that you can fit fewer people into that tight volume.
"One of the primary goals in an opera house is to try to
keep that volume tight and intimate, not just for acoustics but for the visual
intimacy between the performers and the audience. Very often they end up being
more of a horseshoe shape or almost circular shape. In order to create a
sightline to the stage, you do tend to rake the seats more in an auditorium for
an opera or ballet than you would need to in a concert hall. The acoustic
detriment you try to overcome by the intimacy of the space. The higher rake
absorbs more sound. In most opera, you are not looking for a very long reverb.
Some of the greatest opera house have short reverb times, but they don''t
necessarily make great concert halls."
And what is the ideal space? Johnson offers a comparison:
"The Metropolitain Opera is the wealthiest operation and has the money to hire
the very finest singers in the world who can more or less cope successfully with
the very large size of the Metropolitan Opera. Most opera companies now are
building 1600 to 2100 seat rooms, and they will be used by singers who will be
appropriate for the scale of these rooms. You will hear singers in those halls
who would not fare well at all at the Metropolitan Opera."
Designing building and sound
together
When a new performance centre is planned, the acoustician is
often chosen before the architect to provide acoustic guidelines. "It''s really a
good collaborative effort," says Johnson. According to Thomas Payne of KPMB,
architect of the Roy Thomson project, Artec suggested the main changes to the
existing hall and it was up to the architect to make the design meet those
specifications. Sometimes, due to budget, an implementation proceeds step by
step over time. Over the past summer, thanks to a donor who cashed in from the
Nortel bubble, the Winspear Centre in Edmonton installed a new organ constructed
by L?tourneau Organs of Quebec. According to Johnson, "We had already decided
where the organ should be placed. Most concert halls have organs because of the
symphonic repertoire for organ and orchestra. It turns the room into a pipe
organ recital hall, and the pipes create an interesting visual." Having the
organ placed at the centre line, above the choral seating behind the stage, as
in the case of the Winspear, is a favourite design for Johnson. "The choral
seats give the ticket buyers a wonderful view of the conductor and it helps to
get additional seats in the hall," says Johnson.
Having reach the apex of their profession, are there any
challenges remaining for Artec? Johnson demurs, saying, "It''s extremely
important to continue to develop our expertise. We are constantly trying to
discover all things that didn''t work, by looking for shortcomings, by looking
for even the slightest improvements. We are constantly seeking the holy grail
that will be the perfect room." *
Elements of a Good Acoustic Hall
Wood, good reflecting surfaces, quiet lighting and air
conditioning and an adjustable canopy are some elements contributing to making a
good concert hall. According to Doria, the cost of quiet lighting and air
conditioning is not really that much more expensive. "There is a small premium
for quieter dimmers but it is really selecting the right kind of light fixtures
and circuiting them correctly. Starting with a quiet fan unit with the proper
size--which in most cases is not really more expensive than a standard one--and
picking a point on its operating curve where it operates quietly as its normal
operating condition. We design the air ducts so that there is enough length
between the fan and the room so the fan is not heard, and we make gentle turns
in the ducts in order not to generate a lot of air flow noise within the
ductwork itself." At the press conference unvealing Roy Thomson Hall, the
officials proudly announced that every seat was computer modelled acoustically
seven years ago. "Every surface in the room can be assigned an absorption factor
in a computer, to arrive at the probable reverb time," said Doria. The 23
bulkheads serve not only to reduce the volume of the space and give the hall
more rectangular characteristics, its sandblasted maple finish reflects sound
back. Sound-absorbing banners can be lowered to cover the bulkheads to reduce
reverb for amplified concerts. Visually, the most noticeable feature of the new
Roy Thomson Hall is its movable circular and crescent-shaped canopies located
above the stage that house the stage lights, also found in the Chan Centre and
many other Artec halls. The canopy reflects sound back to both the stage and
audience to solve the problem of dry acoustics for the musicians. The idea is to
raise the canopies as much as possible for large orchestral works and lower them
for solo recitals; adjustments can be made during intermission. Before the
September 21 opening, Artec engineers will be working for a month with musicians
from the TSO and other ensembles to arrive at optimal settings. When the
adjustable features are not optimized, the results can be disappointing.
Philadelphia''s Kimmel Centre (another Artec project) opened last December to
mixed reviews. Said Johnson, "The building owners decided to open nine months
ahead of schedule. There were many features that were not installed at the
time."
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