Project designer speaks on acoustics, materials

As a project designer on the Walt Disney Concert Hall, Craig
Webb is responsible for constructing physical models at various
scales and researching the most ideal building materials. A partner
of Frank O. Gehry & Associates, Webb, Gehry, James M. Glymph
and Terry Bell formed the project’s architectural team that
worked with both the Los Angeles Philharmonic Association and
Nagata Acoustics (the hall’s acoustical team) to test sound
quality.

dB Magazine: It has been said that the Walt Disney Concert
Hall will be one of the most acoustically sophisticated symphonic
venues. What features make it so? Craig Webb: The Dorothy
Chandler Pavilion (where the L.A. Philharmonic used to perform) is
a multi-purpose facility. It also houses ballet, opera and musical
theater, so they have what’s called a scenic flytower, which
they use to move scenery on stage. When the orchestra performs, the
tower is covered with (an acoustic) shell because the tower
doesn’t reflect sound. Because the shell isn’t a
permanent feature, it is lightweight and so a poor sound reflector.
The Disney hall is designed specifically for symphonic music, so
the problems of dual use are eliminated. The surfaces are heavier
and reflect sound better.

dB: How do you test acoustics? CW: The first phase is
computer simulation. We build models in a cyberspace program, then
fire sound particles into the room and track them, which produces a
diagram that shows sound particle accumulations and gaps in the
space as it spreads and reflects. The second phase is an optical
test. We put foil over the model’s surfaces and point a laser
at the ceiling and walls to see where it reflects on the seating
and the time it takes for the beam to travel there. In the third
phase, we build a one-tenth size model and send sound impulses at
10 times their natural frequency into the space and record the
sound at different points in the room.

dB: What was the inspiration for the hall’s interior
and exterior design? CW: The hall’s function is to
accommodate music, so we designed the entire facility from the
inside out. The architects wanted a rectilinear space and the
acoustic specialists wanted a curvilinear sculpted space for better
sound. In the end, we compromised and put curved seating in a
box-like room to make it look like a boat on which the orchestra
and audience are sailing on a ceremonial voyage together. That
nautical theme took hold, and we sculpted the ceiling like sails.
Then the exterior followed. When you look at the building straight
on, it looks like what’s called “wing on wing,”
which is a configuration of the main sail and the jib sail.

dB: Why did you choose steel for the exterior? CW: We
were originally going to use limestone. We want to use the heavy
material to imply lightness and movement: music in a static
material. Due to funding problems, the project was shut down, and
to continue, we had to propose a less expensive design. We had just
finished work on the Bilbao (the Guggenheim museum in Spain) and
thought, “˜Why not use steel again?’ The shapes actually
looked better in steel, and the cost was better. We chose the
stainless finish because it reflects the color and light of the
environment. At night, it picks up headlights and sign lights, and
cracks in the facade enable light to pour out, as if to say the
real action is inside.

Interview conducted by Kathleen Mitchell, dB Magazine
contributor.