Originally published in Interiors & Sources

05/18/2005

The Hollywood Bowl

American Classic Is Reincarnated With High-Tech Acoustical Rehab

 

Photo Courtesy of Jaffe Holden Acoustics

On a warm, starry night last summer, the sounds of the Los Angeles Philharmonic and a local university choir washed over a sellout crowd at the newly renovated Hollywood Bowl. In the audience, long-established traditions prevailed. The typical crowd of young families and couples dined from picnic baskets and sipped wine or soda brought from home, much like three generations of concertgoers before them.

But under the shell, a new era was unfolding. For the first time since the Bowl’s construction nearly 83 years earlier, the conductor could hear the orchestra, and the players and choral members could listen to each other for musical cues.

The Hollywood Bowl, safely tucked away in 88 acres of a canyon that isolates it from a noisy freeway and dense residential neighborhoods, has been the summer home to the Los Angeles Philharmonic Orchestra since 1929. It has also served as a convenient, yet memorable, setting for countless Hollywood movie scenes and recorded concerts, securing for it the status of an American cultural icon.

Yet the paradox of this legendary centerpiece of the Los Angeles performing arts scene is that the natural amphitheater has always been a nightmare for musical performers. The stage was too small to accommodate a full symphony orchestra, and sound from the rear of the performance area would reverberate within the shell, preventing musicians from hearing each other play. To compensate, sound engineers used microphones and amplifiers to boost string and wind instruments, but the onstage sound reinforcement tended to distort the overall audio quality of the performance.

In the 1970s and 1980s, Los Angeles County, the Bowl’s owner, and the Los Angeles Philharmonic Association, its leaseholder, attempted a few quick fixes. These included sound-diffusing “sonotubes,” long, cardboard cylinders that were suspended from the top of the shell in an attempt to keep the orchestra’s sound from dissipating. When those didn’t work, they were replaced by fiber glass spheres. Both devices were designed by the modernist master Frank O. Gehry, but neither solved the acoustical problems.

“It was a closely guarded secret that the musicians could not hear the conductor,” Craig Hodgetts, a principal in Hodgetts + Fung Architecture and Design, said in an interview with the Los Angeles Business Journal. “Basically, the conductor would say ‘louder’ and a guy on a recording mixing board turned up the volume on the French horns or whatever instrument, so the audience was getting a second-hand interpretation.”

Eventually it became clear that quick fixes were not going to do the job; repairing the Bowl’s flaws would require drastic measures. So, following a design competition in 1997, the county and association hired a team led by Hodgetts + Fung to complete a $25 million renovation. The original structure was razed in 2003, after lawsuits from preservationist groups were settled. In its place rose a 30-percent larger shell with a state-of-the-art acoustical canopy and lighting trellis.

The challenge lay in designing a new clam shell that physically resembled its predecessor but erased the acoustical flaws. The new Bowl has a 50-foot diameter turntable built into the stage, larger dressing and staging rooms in the wings, and a retractable screen to shade performers from the sun during afternoon rehearsals. Perhaps the most visible acoustical improvement is the 14½-ton aluminum canopy, commonly referred to as the “halo,” an elliptical ring that seemingly floats over the stage.

The halo was designed by Jaffe Holden Acoustics to solve acoustical problems while allowing the architects to maintain the original look of the shell. It uses 29 hydraulic panels that rotate like flaps on airplane wings to adjust reflected sound from string, wind, brass, and percussion instruments. Each panel, coated in ultra-strong plastic called Makalon, took nine weeks to fabricate and deliver.

Except for concertgoers seated directly in front of the stage, the acoustical canopy’s effect was barely detectable last summer when the Los Angeles Philharmonic, along with the Chapman University choir, performed Howard Shore’s Lord of the Rings symphony. But for the musicians - and for the technicians responsible for miking each of the orchestra’s sections for the capacity crowd of nearly 17,500 - it made all the difference in the world.

“It’s the most technologically advanced acoustics mechanism in the country, unlike anything else in the United States,” says Chris Jaffe, principal at Norwalk, CT-based Jaffe Holden Acoustics.

Sound of music

Ironically, it was acoustical clarity that inspired an amphitheater at the site in the first place. H. Ellis Reed, the Bowl’s original developer, discovered the spot while hiking with his father in the hills in the early 1900s. After trekking down to the canyon floor, he yelled to his father, who was standing on an outlying rim, and both men were startled at how well their voices traveled. The first amphitheater opened in 1916 with a production of Julius Caesar starring Douglas Fairbanks Sr., but it wasn’t until six years later when the Los Angeles Philharmonic Orchestra began playing at the Bowl that a backdrop was erected.

A series of temporary designs followed in quick succession. The original plain backdrop gave way to a grand elliptical arch in 1926, which was replaced by a pyramid-shaped structure a year later. The first shell, built in 1928, didn’t last the winter. It was replaced with another shell structure designed by Lloyd Wright, son of Frank Lloyd Wright, which was meant to be temporary but lasted for 75 years.

During most of its existence, the Hollywood Bowl was frequently patched together with temporary fixes, even as the number of uses for the structure grew. By the time it was razed in 2003, Hodgetts recalled, “When you walked up to the shell and looked at it, it was basically a shack. It was really shabby. Things were bound together, taped together.”

Hodgetts said his firm had to balance several concerns when redesigning the Bowl - and acoustics were at the bottom on the list: “Basically there were parameters to be considered: the neighborhood’s needs, the issue of parking, the orchestra’s needs because they were cramped on the stage, and then there was the requirement for road shows and the whole catering thing, which put a squeeze on everything. After that, there was the issue of acoustical needs.”

But Jaffe’s design guaranteed acoustics wouldn’t take a backseat. The steel- and aluminum-trussed frame, measuring 78 feet by 66 feet, is clad in curved, smooth fiber glass. It is supported at a 10-degree angle below the main roof of the structure by inclined tubular steel struts.

The canopy contains an elliptical perimeter ladder truss with a catwalk along the outer ring and four cross-stage triangular trusses to support the acoustic panels and lighting equipment. Up to three stage technicians can access lighting equipment simultaneously. The acoustical canopy can be raised and lowered by means of pistons and nautical-grade winches.

For all of its bells and whistles, Jaffe said the basic design is premised on devices that have guided acoustical engineers for decades: a mix of baffles and reflectors. “We were following a design that has been proven successful for over 40 years,” he said. “We used reflectors so that the overall shape of the outer structure becomes a kind of reverberant chamber.”

Construction management was assigned to the Los Angeles office of MICE Creative, which assembled a team of specialists to make the design a reality. Total Structures Inc. created the aluminum truss system and the acoustical panels. LA Propoint was in charge of theatrical rigging and show control installation, while the show-control design and installation was given to Proskenion Design. Hopper Elmore and Associates were the structural engineers. JR Clancy and International Rigging designed custom winches and temporary rigging and installation, respectively.

Rollin’ with it

The acoustical canopy’s paramount achievement may be its flexibility to accommodate the wide variety of acts that perform in the Bowl during each season. Besides the Philharmonic, the Bowl has to accommodate traveling acts from Burning Spear to Britney Spears, each of which brings along its own lighting, sound, and stage shows.

“The road shows directly conflicted with the acoustical needs because the road shows are miked - they’re not acoustic performances - and the lighting requirements are utterly different from a classical, symphonic performance,” Hodgetts said. “We had lift trucks bearing big lighting trucks, and they were driving through the place where the instrumentalists were storing their Stradivarius.”

Improving acoustics and providing the flexibility for traveling shows turned out to be the most difficult conflict for the architects and sound engineers to solve.

“One of the biggest challenges was the multiple use of the space,” says Jaffe. “Not only did it have acoustical challenges but things had to be moved in and out rapidly from one night to the next. That made the design process very, very difficult. Of all the things we had to put together, the operation of the Bowl and its production needs were probably the biggest challenge for the design team.”

To get around this, the sound panels can be hoisted to the roof and folded to the contours of the shell, while the stage-left and -right catwalks can be dropped so that a semi load of touring equipment can fit on the stage.

“The acoustical trusses disappear inside the dome, and you can bring in a 60-foot clear truss rig,” says Chris Patrick, president and general manager of MICE Creative. “Otherwise it would be in the way, and a touring truss rig for a rock and roll show wouldn’t fit.”

Framing it

When MICE Creative received the contract to build the “halo,” the company’s first decision was to hire Burro Happold Engineers Ltd. to perform an extensive structural review.

“We were on a very, very tight budget,” Patrick says. “No change orders were being allowed, so we had to guarantee to do it at that price. I wouldn’t take on projects without structural reviews.”

That turned out to be a wise decision when several errors in the plans were found. The mechanism connecting the acoustic panels to the trellis originally used a bar system that moved without being secured to the truss, a design flaw that Patrick says would have been “a maintenance nightmare.” Also, MICE Creative tried to reduce the weight of the “halo” by using a mix of aluminum and steel.

“There were some serious flaws in the design and the structure,” Patrick says. “We re-engineered it to reduce the weight, and we put single-arm actuators on every panel.”

When it came time to build the aluminum truss, Patrick turned to Peter Hind, a structural engineer who at the time was a vice president at Total Structures. Hind came up with a series of aluminum beams reinforced with scaffolding.

“Without Peter Hind we would have been struggling,” Patrick says, adding that Hind and his team at Total Structures “were fully understanding in the theatrical aspects of the construction; they built some very large aluminum structures in the past, and this was really an overgrown theatrical truss.”

Since the project’s completion, Hind has left Total Structures to return to his native UK, says Peter Johns, a Total Structures vice president who also worked on the project. Johns says that building the acoustical canopy was one of the trickier projects the firm has undertaken. While the company typically works with 2-inch diameter aluminum tubes on its designs, the Hollywood Bowl project required six-inch tubes.

“It certainly adds to the difficulty of rolling it to the desired shape,” Johns says. “The problem with aluminum is that when you start to heat it, it wants to twist in odd ways. It really was quite a difficult technical feat.”

To keep the aluminum in place, Total Structures had to use large jigs - essentially molds that held the aluminum tubes in place and prevented metal distortion. And there were other considerations as well.

“Even though this is positioned in sunny Southern California, it’s still subject to a lot of weather fluctuations,” Johns says, noting that temperatures in L.A. can vary from high-90s during the day to low 50s at night. In addition, he says, the firm needed to make sure the 14.5-ton structure could withstand an earthquake without collapsing onto the stage below.

To make sure the structure could pass muster, Total Structures put the design through rigorous computer modeling tests known as “finite element modeling,” which Johns says “tests the theory of the design. It has lots of variables you can put into it to test for seismic and weather forces that will be bearing down.”

Once Total Structures had finished manufacturing parts for the acoustical canopy and trellis, the structure was assembled in a former Howard Hughes aircraft hanger in Playa Del Rey, on L.A. County’s west side, to make sure all the parts fit and were in working order. When everything checked out, the structure was taken apart and reassembled on-site in the newly completed Hollywood Bowl.

The structure withstood possibly one of the most extreme weather tests this past winter as Los Angeles experienced one of the wettest rainy seasons on record. Although the region received more rain last year than Seattle, the structure sustained no damage, says Patrick, who recently finished MICE Creative’s winter test of the system. The firm has a 10-year maintenance contract on the structure.

“It stood up well against the rains,” Patrick says. “It drained out perfectly. There was hardly any water in there.”

But the far more important test of the design and construction, Johns says, had already occurred on opening night. “It took my breath away,” he recalls. “Even though I had seen it at every stage of construction, to see the whole thing together was really an eye-opening moment.”

Andy Fixmer covers real estate for The Los Angeles Business Journal.

 


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Bluebeam® Revu® simplifies digital facilities document management from design review to leveraging as-builts, maintenance manuals and O&Ms submittals.

Yaskawa drives offer quality performance for air handlers and cooling towers on the roof to secondary chilled water pumps in the basement

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Our mission is to help our customers manage their buildings' energy costs, improve reliability, and enhance performance while having a positive impact on the environment.
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