Michigan’s venerable football stadium gets a new round of AV updates.
By Dan Daley
Excerpted from Sound & Communications, November 2011
Texas, meet Michigan. At least as far as it applies to college football, the Lone Star State that prides itself on all things big meets its match in Michigan Stadium at the University of Michigan in Ann Arbor. And that nearly 90-year-old bowl recently became even bigger, as a result of an expansion completed this year: Seating now holds just a hair under 110,000 Wolverines fans, both outdoors and in 85 new suites and new press boxes, allowing the stadium, popularly known as The Big House, to easily hold onto its ranking as the largest stadium in the US and the third largest in the world.
New AV Systems
Last summer, The Big House also got a new array of AV systems, most notably a pair of giant new LED screens, each 85′x47½’ in landscape layout, located at opposite ends of the stadium. This reportedly adds to Michigan Stadium’s large-scale “intimidation factor,” which almost certainly contributes to the Wolverines’ ownership of the most all-time wins and the highest winning percentage in college football history, finishing in the Top Ten in the AP NCAA poll a record 37 times.
That kind of confidence allows Michigan to do what few other universities would attempt, even in better economic times: After installing a new sound system in 2010, the school had the nearly new system removed so it could replace the scoreboard with the new digital video edifice, and then reinstalled the previous PA system in it, along with additional components that help it tackle a truly intense challenge: covering a massive stadium with throws as long as 800 feet with a single point-source PA system.
“The use of a [vertical] line array was the big difference,” explained Peter O’Neil, systems designer at TeL Systems (www.thalner.com), the integrator that installed the sound system as well as the video replay camera system and digital audio and video switching and routing systems.
“There weren’t a lot of choices to cover the entire bowl because we didn’t have the architectural infrastructure for a distributed audio system, so we had to go with a pointsource approach.”
However, that wasn’t a drawback as far as the integrator was concerned. Although distributed systems offer better frequency response due to more speakers closer to seats and the elimination of sonic reflection issues in a large stadium, a point-source system provides greater phase coherence. “With either approach, you have certain advantages and certain tradeoffs,” he said.
The main PA system is rounded out with a BSS Soundweb London DSP for system management and distribution, and a Yamaha LS9 mixer for FOH audio, which O’Neil described as “not the fanciest” but which gave him a flexible digital signal path with AES signal capability to interface with the Soundweb in a small footprint for the control room.
Sound Wave Reflections
Sound wave reflections in a large space had to be addressed, and the line array system did that by allowing the system to be more precisely aimed and its horizontal dispersion pattern narrowed to 60 degrees, helping direct the sound away from the tall suite and press box towers on either side of the field, the source of some of the worst reflections. The longer line array design—the latest version increases the hang from four boxes to 13—also means improved frequency range and response because the longer array design means it can take pattern control capability further into lower frequencies and control directionality throughout that frequency range more precisely. The system’s design was helped in part by ray-tracing analysis done by WJHW in 2007, when the 2010 upgrade was in its design phase, because the new architectural additions included a lot of glass surfaces in the suites and new press boxes. The design was refined using AFMG’s EASE predictive modeling software.
One new component that intensified the effort to control aiming and pattern dispersion was the Meyer SB-3F sound field synthesis loudspeaker, a dedicated long-throw device capable of projecting mid-to-high-frequency energy over distances of nearly 1 kilometer (about 1000 yards). The field synthesis DSP achieves a narrow coverage angle (as tight as 7°) using 448 one-inch neodymium transducers as multiple small point sources encompassing a frequency range of 2kHz to 9kHz, to achieve a coherent sound field over that distance. Like the other PA system components, the SB-3F is self-powered, using a multichannel, high-power (9000 watts burst power), class AB/H power amplifier, which eliminated the need to run cabling to an amplifier closet for the massive scoreboard. The SB-3F also runs on Meyer’s RMS remote monitoring network, which monitors system parameters on a Windows-based PC. Eight of the SB-3F speakers were added to the system, placed four per side in a vertical array aimed at precise locations in the south end zone, specifically, at the center of each seating section of the south end zone beginning at the ends of the press box towers, four from east to center, and four from west to center.
The SB-3F solved two problems, according to TeL Systems. First was the need to span the length of the stadium with a high degree of throw; it also helped reduce the effect of sonic reflections that ray-tracing had determined would impact fans in the first 10 to 15 high-cost-ticket rows of certain sections, by focusing the higher frequency direct sound on those sections. Secondly, O’Neil said, “It addressed the issue of air absorbing the upper-mid to high frequencies over that distance. When you get beyond 650 feet—and we have to go 800 feet and more—you’re going to progressively lose a lot of higher frequency information. This was a unique product that let us extend frequency response out to those distances, and that means you’re extending the fan experience, as well.”
Full frequency range coverage of the entire stadium is important because sports fans have come to expect it outdoors as well as indoors, but it took on added significance at Michigan Stadium because O’Neil has a deeper interest in the project than the typical systems integrator might: Since 2002, he’s been the TeL Systems employee responsible for game day operations as the stadium audio engineer, a unique situation that came about when he worked on the PA system at the stadium for Creative Audio, which later merged with TeL Systems as the latter’s audio division. He said that TeL Systems’ subsequent successful bid on the 2010 PA upgrade was simply serendipitous. His involvement with Michigan Stadium’s audio operations extends to him using Sennheiser shotgun microphones on poles to mic the University’s Michigan Marching Band (MMB), a 350-member ensemble that would be considered loud under normal circumstances but whose volume is tested by the cavernous stadium. Although many broadcast mixers purposely position microphones in front of marching bands for collegiate football broadcasts, it’s nearly unheard of to see them miked for inclusion as an element in the PA sound, but that’s what O’Neil does regularly.
“With the PA configured with these components now, we can distribute the marching band [audio] at full fidelity and full-frequency music response, as well as provide full-frequency response for program music and audio-for-video,” he said. WJHW’s Mark Graham, who has designed systems for dozens of college stadiums, was singularly impressed. “Having the marching band coming out of the PA system at 90dB is pretty staggering,” he offered. “They’re loud and they sound great.”
WJHW designed and TeL built and installed a control room to manage audio and video content for the scoreboard. A 24-channel fiber snake runs from the scoreboard to the control room situated about 500 feet from the north scoreboard, distant but nonetheless closer than the old control room it was replacing, said Graham. TeL also installed fiber and copper for video and control cabling between the scoreboards and the control room, as well as hybrid ad triaxial cabling to the new broadcast truck interface area, located across a main road from the stadium. “We’re approaching the limits of HD capability from the field at that distance with the triax, so fiber cable was essential,” stated Graham.
Other sound systems include a combination of ceiling- and surface-mounted Atlas FAP42T, FAP62T and SM52T speakers, as well as pole-mounted Community R and W Series speakers at the stadium’s entrance gates that run a looped message from a Marantz DNV755 digital networked audio player about stadium rules and other information as fans make their way in, but can be overridden globally or locally with more urgent information. Graham said that the distance that the gates are from the nearest AV closet—more than 1000 feet in some cases—led to the choice of using handheld IED 500HH paging microphones that take DC power from a pair of 10-gauge wires to power a microphone preamp internal to the microphone and send a line level signal back to the system, thus maintaining a high quality audio signal. “It works surprisingly well,” said O’Neil.
The new indoor club areas also share in the upgraded audio. Although the new glass façades on the clubs are designed to keep out extraneous noise, WJHW designed in a feed, controlled using a Crestron TPMC-8WL touchpanel operating a Crestron MC2E processor that interfaces with the BSS London system via GPIO control ports, from the PA that sends program, announcement and ambient sound to the private lounges. “We didn’t want to have high-value patrons feel isolated behind the glass, so we brought some of the crowd and other sounds inside,” O’Neil stated.
By The Boards
The scoreboards are indeed massive. More than 4000 square feet of display for each is made up of over panels that were assembled into 18 sections by TS Sports, which installed the LED video displays based on Lighthouse Technologies’ StarVision 16mm SMD panels (Surface-Mount Device, referring to the configuration of the LEDs on a single platform) that produce an overall HD image that’s 900 pixels tall and 1632 pixels wide, each made up of three LEDs for a total of 4.4 million diodes. “Michigan Stadium features the first outdoor 16mm SMD video display in collegiate athletics,” said Matt Ritter, vice president of TS Sports. According to Ritter, the assembly of the video screen components is simplified by a jagged-edge design on the sides of the 9600-plus individual modules that facilitate alignment across the entire display. “It’s like a very large puzzle: The challenge is making sure that each piece fits exactly right. When done right, the alignment is perfect and there are no visible seams in the image,” Ritter said. Cabling is prewired on the rear of each assembly and is plugged in as the structure moves upward, with the signal daisychained from panel to panel by Lighthouse Technologies processors. The new LED video displays are 40% larger than the first-generation LED displays they replaced, and required solid concrete footers and additional steel beams for internal support. The rigidity of the structures was based in part, but critically so, on wind load data supplied by Ann Arbor and Michigan state meteorological departments. The display’s content is controlled by Click Effects software, which pulls graphics and prerecorded video from a server, which is combined with realtime video from the stadium’s three HSC300K handheld cameras and solomo replays cameras via a Harris PT Series switcher in the control room.
Fitting the PA into its new home in the upgraded scoreboards was almost anticlimactic, though it had its own stresses, thanks to the need to get the entire project done in time for the first game in August: a little more than a week to reinstall the PA system, O’Neil recalls, featuring a lot of “creative rigging.” TeL Systems disconnected the existing PA systems’ cabling connections inside the old scoreboard, taking the cabinets back to its shop and readying them for reinstallation along with the new components, including the SB-3F speakers and a Meyer Sound Galileo loudspeaker management system, which provides system drive and alignment.
The University of Michigan stadium project was all about getting sound and light from one end of a very big place to the other. But as a result of some big systems, U of M’s “Big House” keeps its Texas-sized bragging rights for the college football circuit.
About TeL Systems
Over the last 40 years, TeL Systems has specialized in the design, installation, and maintenance of educational, industrial, and broadcast video and audio systems. Working closely with the customer, we provide assistance in every phase of the project. Services include consultation, technical design, system installation and training. We also provide post-installation services such as maintenance, system expansion, upgrades, warranty service and repairs.
At TeL Systems, we realize our reputation depends upon product support and services after the sales and that these services are not only paramount in your search for a reputable dealer, but are the key to your ultimate satisfaction. We place a high emphasis on our service department and have many long-standing customers to show for it.
We are employee owned, and proud of our company. Any firm that wishes to maintain such a wide array of products and services must operate with a high degree of professionalism. We spend much of our time and resources training our workforce in the latest in technology, industry trends and professional solutions so that our workforce maintains the highest level of customer service; something our customers have learned to expect.
TeL Systems is based in Ann Arbor, Michigan and is a proud member of PSNI. http://www.thalner.com/
Professional Systems Network International (PSNI) is nationwide network of independent audiovisual and unified communication integrators and service providers. Formed in 1986, PSNI brings together selected best-in-class integrators (affiliates) who share a common commitment to ensure the highest standards and integrity of the industry. Ongoing continued education focused on client-centered solutions and best practice sharing ensures PSNI affiliates continue working independently and collectively through the PSNI Enhanced Service Network (ESNet) to deliver an exceptional customer experience, regardless of the location of the client. PSNI affiliates design and implement audiovisual and presentation systems for government, K-12 schools, higher education, corporations, medical, houses of worship, broadcast and cable, digital signage, hospitality, legal and residential.
For information regarding PSNI, go to http://www.psni.org.
Excerpted from Sound & Communications, February 2012. Read the entire story: http://viewer.zmags.com/publication/17adda68#/17adda68/54