Since the turn of the 20th century careful listeners
have been obsessing over acoustics. It’s been a dynamic period of fads, experimentation, intuitive trials, and gross
errors. The latest trend is narrower halls, which is characteristic of the great European halls that create such nostalgia.
So we’re coming full circle.
The antique halls are narrower than those we could build later
with reinforced concrete and steel girders. In the 1880's the beam span of a hall was limited by the strength of timber. Halls
were built narrow in order to carry roof loads without resorting to obstructive columns inside the hall. Acoustics was a roll
of the dice, but most halls were winners.
As roof spans got wider halls could hold more people and fit
more seats near the stage. So they got progressively wider. But larger auditoriums came with a loss of acoustic quality, such
as a dip in lateral reflections. For example, cavernous spaces like London’s Royal Albert Hall aren’t great places
for a concert– they’re better suited for basketball.
In the 60's a lot of multi-purpose auditoriums were built that
were expected to do everything: musicals, operas, ballet, symphonic concerts, symposiums, lectures, and community meetings.
So many acoustic compromises were made that the halls didn’t serve any function particularly well.
This led to the tricks of ‘variable acoustics’ in
the 70's. False ceilings, heavy draperies, and flex-walls could be removed or replaced to accommodate different programs from
opera to rock. For the most part, these techniques fell short on many counts. Fan-shaped halls and reverse-fan-shaped halls
didn’t work well either.
In the 80's there was a push from architectural preservationists
to retrofit historic buildings for new uses. A slew of great but abandoned structures were repaired and restored integrating
modern infrastructure and materials. In Paris, the great Orleans train station was adapted to house the Museum D’Orsay,
which quickly became a treasure and is wildly successful.
But it’s trickier to re-use buildings for concert halls.
In San Diego, Symphony Hall was installed in the old downtown Fox movie theater. Retrofitting a movie stage just doesn’t
cut it. Acoustics were lame. Twenty years later they’re still fussing with this and that to improve the sound, to no
avail. It would still be a better place to see a movie with a bag of popcorn than listen to the philharmonic orchestra. Musicians
deserve better.
During the 90's it became clear there were lessons to be learned
from past success and failure. With high-quality acoustics rising in import, with architects vying for the challenge of designing
for sound, with acoustic engineers in demand– came substantial advances.
It became understood that reflected sounds produce slightly
different signals at the left and right ears. The differences are subtle, but dissimilar enough for the brain to perceive
an enhanced "spatial" quality to the musical signal in a narrower hall– giving the impression of a fuller immersion
in sound.
New halls are being built leaner, for 1800 to 2500 listeners.
The acclaimed Bridgewater Hall in Manchester, Benarnya Hall in Seattle, and Disney Hall in Los Angeles– all seat about
2500. Testing has shown that symphony acoustics are best in halls seating less than 3,000 people. And the old shoebox shapes
(think Boston and Vienna) continue to be winners. So our future lies in our past.
But now that acoustic science and architecture are interlocked
in a thrilling new discipline– construction money has petered out. A new concert hall project takes $100 million–
plus. Cities and non-profits are strapped for funds. Some argue that symphony orchestras only appeal to the aged– that
audiences are dying off. So now that design-driven computer testing almost assures great acoustics-- there are new deterrents
to building great new halls.