SANTA CLARA -- After watching their team done in by the din at Seattle’s CenturyLink Field, 49ers fans are wondering if they will be able to return the favor when their team’s new stadium opens next year.
The answer: Probably not.
The potential decibel level at Levi’s Stadium won’t be clear until the 68,500-seat facility has its first sellout. But unlike the Seahawks’ stadium, the design of the 49ers’ future home doesn’t lend itself to capturing noise.
And for that, you can blame the nice, California weather.
Seattle’s infamous rain inadvertently created the loudest stadium in the NFL. More than 70 percent of CenturyLink’s seats are covered by the stadium’s massive canopies, which arc toward the field from either side like twin parabolas. Designers also wanted to achieve a college football-like atmosphere. So they placed the seats near the field and installed aluminum benches – which when stomped on create a racket – in parts of the stadium.
All of that noise hits the curved walls of the stadium and is sent back down to the field. Monday against the Saints, the Seattle crowd set a Guinness record by achieving 137.6 decibels.
Andrew Barnard, a research associate in the structural acoustics department at Penn State’s Applied Research Laboratory, said there are two main architectural ingredients to a noisy stadium.
“You want fans as close to the field as possible, and you want to have highly reflective surfaces behind and above the fans,” he said. “And those are two things the Seattle stadium has going for it.”
Whereas Seattle’s stadium shields the rain, the facility in Santa Clara’s welcomes the region’s abundant sunlight. It has a large lower bowl and places fans closer to the field than at Candlestick Park. But the stadium’s central theme is its openness. It also has gaps on either side of the suite tower on the west side, which will allow decibels to escape into the ether.
“If the stadium is more open, then that acoustic energy can’t build up inside,” said Michael Thill of the acoustical engineering firm Illingworth & Rodkin. “I don’t want to go out on a limb, but my sense is that it’s not going to be as loud because of the openness.”
Thill helped perform the noise analysis for the stadium’s environmental impact report, which involved measuring the sound at a 49ers-Jets game at Candlestick Park in December 2008.
Thill notes that Brett Favre was the New York quarterback and that the 49ers won. He said the roar probably was representative of a typical game.
The noise level during that game mostly ranged from 78 to 92 decibels and, at one point, shot up to 103 decibels when the 49ers scored a touchdown.
Thill, however, notes that there were key differences between his measurements and the Guinness readings in Seattle. For one, he was interested in the noise escaping the stadium and was located at the top of the stadium, not at field level.
The other major factor when it comes to stadium noise, the sound experts said, are the fans. The more raucous the crowd, the harder it is for the visiting team.
And when it comes to rowdiness, Seattle fans have reached world-class status.
Monday’s blowout over the Saints not only produced a record for crowd noise, it produced a measurable earthquake. Seismologists said a minor earthquake occurred during defensive end Michael Bennett’s 22-yard fumble return for a touchdown in the first quarter. A small earthquake also was recorded during Marshawn Lynch’s 67-yard touchdown run in the 2010 playoffs.
How does Candlestick Park, which seats more people than the 49ers’ new stadium and which does not have openings, measure up in terms of noise?
“Uh, I think it’s good,” said Seahawks coach Pete Carroll, who was born in San Francisco.
“I’ve been going there for a long time,” he said. “... I feel real comfortable taking our team in there, but it doesn’t mean their fans aren’t going to go crazy and do everything they can to give their team every advantage. I understand that they’ve already been asking for that.”
Indeed, earlier in the day, Carroll’s counterpart urged fans to give the 49ers on Sunday the same kind of home-field advantage the Seahawks enjoy.
“I would hope for that this week, that Candlestick will get cranked up,” San Francisco coach Jim Harbaugh said. “Make it a real great environment, because it’ll be a great football game. If this doesn’t fire you up, if this doesn’t fire up the fans, then what does?”
Then Harbaugh answered his own question.
“I suppose Abraham Lincoln riding across the field with a frock and a top hat, riding a horse, waving an American flag,” he said. “I doubt that would fire them up, if this game doesn’t fire them up. The people that really love football would be fired up by this matchup.”
Read Matthew Barrows’ blogs at www.sacbee.com/sf49ers and listen for his reports Tuesdays on ESPN Radio 1320.