The sun's rays stream through the huge trellis of crisscrossing steel pipes, bouncing off the stainless-steel ribbons that adorn the stage house of the new Jay Pritzker Pavilion at Millennium Park. It is late June, and all ears are on the Grant Park Orchestra. The ensemble is rehearsing for the first time on the stage of the Grant Park Music Festival's new permanent home, in preparation for the pavilion's inaugural gala concert Friday night.
More specifically, everyone's attention is focused on the electronically reinforced and enhanced sound of the orchestra. The pavilion's unique and sophisticated new sound system is being put to its first "expert listening session," as officials are calling it.
While principal guest conductor James Paul cranks up the thunderous "Battle on the Ice" sequence from Prokofiev's cantata, "Alexander Nevsky," acousticians, sound engineers, Grant Park and city officials, and invited guests swarm like ants over the 4-acre site, scrutinizing the sound that is spilling from a sea of loudspeakers suspended from the trellis, grouped in clusters at the proscenium, perched on pylons at the stage sides and bordering the audience area.
The orchestra is forced to compete with the din of jackhammers, diesel engines and construction noise in a nearby tent where artist Anish Kapoor's "Cloud Gate" sculpture is being installed. To compensate, the audio mixing person pushes the sound levels way up. There are moments when the music emanating from the speaker clusters feels pleasingly natural, but this is far from the "virtual concert hall" sound that had been promised.
That was a month ago. Since then, several other sound rehearsals have taken place at which numerous adjustments have been made to the system, various configurations of stage microphones have been tried and the original audio mixing person has been replaced. The sound quality is said to have taken a dramatic spike. On the eve of Friday night's Pritzker Pavilion gala inaugural concert, the sound engineers of the Talaske Group the Oak Park acoustics and audio consulting firm that designed the park's new audio system insists they've learned from the trials and that the system is ready.
It looks as if the Grant Park musicians already have learned a great deal about "playing" the new outdoor facility. They love the stage shell, which encases the orchestra in curving panels of Douglas fir that can accommodate a full-size symphony orchestra and a chorus of 150. They appreciate the orchestra risers, specially designed by Talaske engineers, that allow them to feel bass sonorities the length and breadth of the stage, making it far easier to play together than at their former venue, the Petrillo Music Shell, which they are overjoyed to be leaving."From the podium point of view, you can now hear easily what is coming from the far sections of the orchestra," Paul says. "The sound the orchestra players hear allows them to relax. This is the payoff: We all now feel the orchestra can play truly piano and know we will be heard out in the audience."
Charlene Zimmerman, the orchestra's longtime principal clarinet, agrees. "This is probably Chicago's finest outdoor stage," she says. "During the break in our first rehearsal onstage, I went to [Grant Park artistic and general director] Jim Palermo and said this was the first time in my 27 years in the Grant Park Orchestra that I've been able to hear the cellos and basses."
She is equally positive about the quality of reinforced and enhanced sound the new system delivers to the audience. "I listened to the orchestra from various places on the lawn while they played the system at four different levels," she says. "The sound was unbelievable clear, natural and balanced from the front to the back of the lawn. When you hear the sound, even from far back, you think, 'Oh, my gosh, this is like being in the same room with the orchestra!'"
So what makes the new Millennium Park sound system unique?
The trellis effect
The Pritzker Pavilion claims to be the first orchestral venue that distributes sound using an overhead trellis on which loudspeakers 52 in all mounted in precise concentric circles radiate from the stage. The system, moreover, is the first of its type created to work equally well for symphonic and choral music, blues, jazz, rock and other genres. It uses four enhancement microphones for the orchestra, four for the chorus and up to 48 smaller mikes to reinforce particular instrumental sections if needed.
Actually the audio setup comprises two integrated systems. The first one reinforces the music, creating the volume that brings out detail and clarity in the music. The second is a sound enhancement system designed to simulate the concert hall experience, enveloping the audience in what the Talaske people call "running liveliness." Each cluster of loudspeakers has reinforcing and enhancing components. The systems are controlled by two or more audio engineers stationed at a mixing console located in the center of the seating area.
The Pritzker system is programmed to create a different acoustical environment for different programs, or even different works on the same program, according to Richard Talaske, president and principal consultant of the Talaske Group.
"Switching the enhancement system will be as simple as pushing a preset button," he said. "We can tailor the amount of clarity and reverberation to match the needs of the repertory, even as the music is being played. This actually will provide more flexibility than you would be able to accomplish by purely acoustical means in a standard concert hall.
"We are basically creating a facility that has its own acoustic signature," Talaske said. The stage was not designed to function as a natural amphitheater, nor will the sound system completely shut out traffic noise during concerts. Performances still will be subject to the vagaries of Chicago's summer rains, temperatures, winds and humidity, and only listeners seated within 80 feet of the stage will have a roof over their heads.
Still, there's no question the new audio system will shield patrons from the urban din much better than the tinny amplification at the Petrillo shell. Indeed, concertgoers will be struck by the sonic intimacy of the music pavilion (which seats 4,000) and its bowl-shaped lawn (which can accommodate an additional 7,000).
More than six years in the making, the Talaske-designed audio system was endorsed by city officials, the orchestra players and audience members in 1998 when a small-scaled prototype was introduced at a Grant Park festival concert at the Petrillo shell.
Frank Gehry, the architect for the park's BP Bridge and Jay Pritzker Pavilion, normally works in close collaboration with acousticians on big concert hall projects such as Los Angeles' new Walt Disney Hall. But for the Pritzker project he and the Talaske consultants worked almost entirely independently of each other. Their one major area of collaboration was determining where the 52 loudspeakers were to be mounted and how they would be distributed. The Talaske team favored putting the speakers on poles within and around the perimeter of the seating area, which is standard procedure for outdoor venues that use audio systems.
Defines the space
Gehry came up with a better solution the overhead trellis. Not only does this massive steel latticework support the speakers and lighting, it also defines the performance space, providing a transition from the surrounding park to the virtual concert hall. The trellis also serves an aesthetic and psychological function. "It makes the audience feel they're part of something important," Gehry said. "It's an example of form and function coming together to make a greater whole," added Jonathan Laney, the Talaske Group's senior audio consultant.
Whether it involves electronics or not, acoustics is never an exact science. The Chicago Symphony extensively reconfigured Orchestra Hall seven years ago to improve the acoustics and only made the sound worse. Efforts to remedy the problems are ongoing.
Talaske insists the Millennium Park's sound system is an entirely different matter.
"We know what the public is about to experience, so that makes us even more excited," he said. "To have the opportunity to bring great sound quality to the public, to let them experience what is possible with today's technology, is for us very satisfying."Copyright © 2015, Los Angeles Times