Coming Home
Nov 1, 1999 12:00 PM, Jack McLean
Designing and installing a powerful, intelligible sound reinforcement system for the new Cleveland Browns Stadium and the fans who eagerly awaited the return of their football team.
The Cleveland Browns are back, thanks in part to a beautiful new 73,200-seat stadium complete with a host of first-class amenities, including well-conceived and executed sound reinforcement systems. The Browns, one of the most storied franchises in the National Football League (NFL) for more than 40 years, effectively left Cleveland in 1995 when the franchise owner received a lucrative stadium package to transfer the team to Baltimore. Nevertheless, the team name and distinctive uniforms remained the property of Cleveland, and the NFL promised that an expansion franchise would be awarded to the city with construction of a new stadium.
Already in the midst of an impressive downtown renaissance that has resulted in the construction of new professional baseball and basketball facilities in addition to the Rock `n Roll Hall of Fame and other structures, Cleveland responded quickly. Designed by HOK Sports Facilities Group, the new Cleveland Browns Stadium, completed in time for the return of the team during the 1999 football season, is a glass, steel and structural concrete monument to the city's grit and determination and their undying devotion to the Browns.
The stadium, designed primarily for football but also capable of hosting soccer matches and other large-scale events, was built at an estimated cost of $283 million. The city oversaw the two-year construction process and managed funding, raised from a variety of public sources. Well into this process, the NFL selected the team's new ownership from a field of candidates, which is now in charge of stadium operations.
Located at the site of its predecessor, Municipal Stadium, on the banks of Lake Erie, careful consideration went into the facility's integration with its downtown surroundings. Gaps in the seating bowl allow visitors on the outside to view the field and inside of the stadium, and in turn, the same openings allow fans to see the downtown skyline. The north concourse, meanwhile, offers a view of the lake, the nearby North Coast Harbor and the shipping activity at the Port of Cleveland. Even the facility's name is unique in this day and age of corporate sponsorship, remaining true to the city and team rather than being auctioned off to the highest bidder. (Think of 3Com Park, Cinergy Field or Bank One Ballpark.)
Multilevel seating decks surround the playing surface, broken only by the gaps between the south concourse and each end zone seating section. The primary seating levels on the concourses are separated by 148 luxury suites and 8,600 club seats, while both end zones offer one large seating section, each backed by Daktronics ProStar video screens measuring 279 949 (8.2 m 28.7 m). The entire east end zone is dedicated as the Dawg Pound, an area reserved for the most voracious Browns fans who often don dog masks and show their approval for the team by barking and showering the field with dog biscuits. Other amenities include two large club lounges in the north and south concourses, as well as a Browns hall of fame, restaurant and team shop.
Bidding process
Sound Com Corporation, a leading sound, video and security systems integration firm based in Berea, just outside of Cleveland, spent several months implementing a range of sound reinforcement systems at the stadium, providing not just installation but a wide range of value-added engineering services. Specification of these systems was formulated by Wrightson Johnson Haddon & Williams (WJHW), Dallas.
In mid-1998, Sound Com, along with several other systems firms, was asked to supply a bid for their services. These bids, however, were submitted as part of the overall electrical contracting package, made up of eight different divisions. Ultimately, the electrical contracting bid as a whole was rejected by the city with all systems integrators asked to tender individual proposals. Sound Com emerged from this process as the winner with its work commencing in the fall and spanning the next several months.
A trio from the company led the systems effort, interfacing with both WJHW on crucial design issues and the various contractors and construction crews involved with the project.
The team included system integration specialists Simon Davis and R. Dave Kocias, as well as support engineers Brendan Dillon, George Lentz and Brian Zaremba, who, in addition to supervising on-site installation, deployed a number of innovative custom engineering solutions.
In brief, the WJHW specification called for a distributed sound reinforcement system to cover the stadium bowl with vocal intelligibility given top priority. A wide range of systems, many of them 70 V, needed to be deployed in concession areas, restrooms, clubs, press facilities and other spaces, and all of these systems needed to be centrally controlled from the sound booth, located on the suite level in the south concourse.
Special assistance
>From the outset, the harsh elements of Cleveland were of concern to Sound Com. Dramatically varying temperatures and constant moisture from the lake, as well as the more than occasional driving rain and snowstorms, needed to be accounted for with regard to the loudspeakers covering the bowl. Although some options already existed, none of these met the performance standards called for in the design specification.
"Maintenance is a big issue in a project like this," said Davis. "Some of the speakers in the bowl are very hard to access after installation, and besides, they should be designed to last as long as possible as a benefit to the customer. We did a lot of investigation but could not find certain models the project required offering the proper performance criteria while also being extremely impervious to the weather."
Sound Com found a willing partner, Community Professional Loudspeakers, to help address this issue, based on the company's recently introduced WET loudspeaker series. Working with Community's Bruce Howze and John Wiggins, several custom WET loudspeakers were devised to meet all environmental and performance parameters. In fact, the result proved so good that Community subsequently developed an entire line, called the Custom WET series, incorporating the elements first defined with this project.
Custom WET series loudspeakers, available in four sizes, are crafted of hand-laminated fiberglass that is also used for the driver baffles. System installers have a choice of two-way, three-way and low-frequency loudspeakers with passive or electronic crossovers, as well as a choice of low-, mid- and high-frequency drivers, along with a choice of custom dispersion patterns. Drivers constructed of weather-resistant materials are another choice, and in a neat trick of engineering, Community used the properties of these materials to enhance acoustical performance rather than having them be a deterrent. Additional design variations include choices of enclosure orientation, heavy-duty rigging points and custom colors for the cabinet and grille.
"This is the first time that designers and installers have the choice of configuring a weatherproof system to their specific parameters. The enclosure size chosen determines both the low-frequency performance capabilities of the system and the range of pattern control offerings," said Howze. "The carbon fiber used for midrange cones and woofers offer superior strength-to-mass ratios, while the polyimide used in the high-frequency diaphragms offers excellent flexural strength, resulting in very good sonic characteristics."
Davis said, "We're employing two models at the stadium, one for lower output needs and the other for higher output requirements, and both work extremely well. In short, we're very glad we approached Community."
Another valuable contributor from the manufacturing side was Crest Audio. All power amps for the project are Crest, under NexSys control. As the myriad amp racks for the various systems were being assembled at Sound Com's facility prior to installation, Crest provided consultation and also arranged for one of its technical staff members to check each rack in person, verifying all configurations, wiring and connections.
Totally distributed
"The number one priority for the bowl system is intelligibility, which naturally lends itself to a distributed approach," said Dillon. "On this project, it's reasonable to estimate that the furthest distance a loudspeaker has to cover is about 50 feet (15.2 m), less in most cases."
Mounting the hundreds of loudspeakers safely and effectively required fabrication of a variety of custom brackets, which Sound Com developed with Caravan Industries of Elyria, OH. "Safety was again our number one concern, along with resistance to the elements," Davis said. "This process was also more challenging than usual because some of the loudspeakers being developed for the project weren't even finalized yet."
Sound Com also elected to go beyond the specification on several accounts, most notably in terms of the amount of rotation of each loudspeaker the brackets would allow. The spec called for 5degree rotation; the end result offered 45degree.
Dillon said, "We felt the added flexibility was needed, first, because some of the loudspeakers weren't complete, second, for more precision in aiming, and finally, for easier maintenance. In fact, some of the loudspeakers on the lower levels can be rotated back far enough for servicing from the aisle without need for a ladder or scaffold."
Upper-level seating on both north and south concourses is covered by groups of three loudspeakers in custom brackets mounted to the rear canopy. One loudspeaker fires forward; the second is aimed almost straight down, and the other fires to the rear. The vast majority of these loudspeakers are Peavey Electronics Impulse 200s, offering a compact two-way design with exceptional weatherproof capabilities. These groups are mounted for optimum coverage of specific seating sections, given each loudspeaker's 90degree 45degree coverage pattern. Every other group substitutes a compact WET series model 322 loudspeaker for front-firing coverage, where more output was needed to reach select lower-level seating zones.
Coverage to the majority of club seats on the concourses is supplied by single Custom WET series model 315 loudspeakers mounted to the face of the upper level; in other words, they are directly behind these seating areas. Spaced about 25 feet (7.6 m) apart, these loudspeakers originally were to be mounted horizontally, with the cabinets including dual 12 inch (305 mm) woofers. Conflicts with signage necessitated that they be mounted vertically with their horns rotated and a single 15 inch (381 mm) woofer replacing the dual 12 inch woofers, giving the enclosures a lower profile.
Shadowed areas immediately beneath these loudspeakers receive coverage from either Renkus-Heinz (R-H) TRC61W (south concourse) or TRC81W (north concourse), both compact two-way loudspeakers that are mounted horizontally and fire almost straight down. Open-air luxury suite seating immediately behind this area are each served by dual JBL Control 28 loudspeakers.
Finally, the lower level of the bowl features tandem coverage from Custom WET series model 322 loudspeakers and Impulse 200s. These two models, again on custom brackets and attached to the face of the club level, are alternated. Model 322s supply longer-throw coverage, while the Impulse 200s handle nearfield, firing almost straight down, with the zones covered by the two feathered together for smooth coverage without hot or dead spots.
Both end zones have virtually identical loudspeaker packages. Three Community FCH6051 mid-high loudspeakers are paired with three Community R6 low-frequency systems (all weatherproofed), mounted atop the video board structures behind the seating sections. The R6 uses six 12 inch (305 mm) drivers in a unique manifold configuration for long throw and high output. These combos cover the upper portion of each end zone, while the lower section is blanketed by another WET series model 322 and Impulse 200 pairing, used in the same manner as they are on the concourses.
"All of these loudspeakers were ideal for this application," said Kocias. "They offered the prerequisite resistance to the elements and placed a premium on vocal intelligibility. You certainly don't have any problem understanding what is being said."
Driving components
Close to 150 Crest power amps, all housed in Middle Atlantic racks, drive the bowl system. These racks are distributed among six secured rooms throughout the club level of the stadium. Crest CKS series amps handle most of the loudspeakers, generally driving 4 V loads. Crest 9001s are deployed for low-frequency sections of the higher output WET series loudspeakers. As mentioned, all power amps are under Crest NexSys control, with its version 3.0 software, implemented and tailored for this application by Sound Com, hosted on a Dell Dimension PC in the sound booth.
"We have been extremely pleased with NexSys on this project," Dillon said. "All amplifiers are sequentially turned on and off, and we can view and modify this from the control position. In addition, having access to level control and status indicators really saves a lot of walking around. We know what every amp is doing any time we choose to take a look."
Signal processing of the bowl system is done in the analog realm. "It's certainly been popular to use digital processing mainframes in stadium systems, but we have some apprehensions about that approach," Davis said. "It seems that sometimes all of the capability they provide can actually complicate the system too much. Sometimes more is not necessarily better. Plus, you're placing a lot of faith in one single unit, and if it fails, you can get into trouble without options."
As a result, White Instruments 5024 crossovers and Klark-Teknik (K-T) DN7204 delays form the heart of signal processing for the bowl system, housed in the sound booth. Both units also include equalization; the White units supply overall equalization while the K-T units are used for more individual tailoring and tweaking by zone. Further equalization, as well as level adjustment, is accomplished on the Soundcraft K2 mix desk established front/center in the booth. Two Crown CM-311 headset mics for PA announcement purposes, are first routed through Symetrix 528E vocal processors for optimization.
Two 360 Systems DR-522-16 digital playback machines supply recorded messages to the bowl system, as well as to many of subsidiary systems throughout the facility. A Click Effects hard drive system supplies various audio playback and sound effects, while Marantz CD and cassette players can also be used. An audio feed from the adjacent video control room, which accompanies programming shown on the video screens, is kept consistent with a Symetrix 425 compressor/limiter.
"We've even put a delay channel on the Mackie monitor speakers in the booth so that they are in sync with the bowl system when the window of the booth is open," Kocias said. "The system operators really appreciate this. Overall, the booth is set up pretty well with anything that the operators might need right at their fingertips, and in essence, they shouldn't have to do much with the system through the course of a game besides verifying that the everything is operating properly and occasional minor adjustments."
Another facet of the bowl system is the ability to put a pretty impressive array of equipment on the field for pre-game and halftime festivities. Sound Com created several custom panels that can accommodate several Community XLT48E monitor wedges in addition to 48 mic jacks all directly linked back to the console. Two Vega R-662A UHF wireless systems are also available with antennas and receivers mounted in a rack in the booth. Four channels of the house-wide Clear-Com intercom system can also be accessed on the field, and this is interfaced with a Telex RTS system used by the video production crew. The intercom system is also accessible at all remote equipment rooms.
Ancillary work
Just the equipment list for the project spans more than 10 pages in length, and it serves as a good indicator of the sheer amount of systems work that Sound Com poured into the project. Hundreds of ceiling loudspeakers, from such manufacturers as Lowell, Atlas and OWI, serve a host of common areas such as concession stands, restrooms, gates - in short, it is virtually impossible to be out of reach of paging announcements and other programming. It's all driven in 70 V mode by Crest CKV power amps also on the NexSys control bus and located with the bowl system amps at several stadium locations.
Sound Com deployed a Peavey MediaMatrix MM740 Mainframe to provide all processing for these systems, in addition to establishing an impressively flexible signal routing scenario. Located in the sound booth, MediaMatrix shares the Dell PC with the Crest NexSys amp control software, done in the interest of space savings and ultimately an arrangement that has proven to function in a satisfactory manner.
"With the way we've set up the MediaMatrix, we can send independent signals - all optimally processed - to more than a dozen subsystems serving different zones and areas. You select the source material and where you want it to go, click, and it's done," said Dillon.
All source feeds, such as the PA announcements, home radio broadcast and TV broadcast are all routed to AMX Axcent3 integrated controllers, in turn linked to AMX touchpanels in both club lounges. This provides club hosts the opportunity to select any source to be played in the club, or, they can choose to play music on a local Denon DCM-60P CD player. Mic panels in these rooms allow localized presentations to be held as well.
All restroom and concession area systems have time delay parameters programmed into their feeds from MediaMatrix, ensuring that they are in sync with the bowl system. Sound Com also established auto gain riding in the software, which automatically adjusts the level of these systems in relation to the output of the bowl. Line-level source signals to the furthest of these ancillary are transported via fiber optics, with BEC Technologies SigmaNet A/D and D/A converters carrying 10 channels.
Two press conference/interview rooms have their own discrete system electronics feeding ceiling loudspeakers. In both cases, they include TOA M-900MK2 automatic mixers linked to several mic jacks in the room, with several remote volume controlsinstalled on the walls. The press room, ensconced on the club level is served by its own independent system, with a Peavey A/A-8P mic line preamp feeding a Phonic Ear PE550T FM base station. It provides RF signals to up to 48 PhonicEar 300RS receivers available to members of the press - anyone wanting the press feed gets it without disturbing others working in the location.
Final phase
Sound Com's aggressive preparation and adherence to a strict system implementation schedule paid off in the end with the system installed, completed tested and optimized well prior to the kickoff of the 1999 season. The tuning process commenced with verification of all ancillary systems - not an easy task. After every single loudspeaker was determined to be working properly and then set to proper levels, it was time to move on to the bowl system.
WJHW and Sound Com teamed up for this portion of the project, using a TEF 20 analyzer to aid the process. "We had already roughed in the settings established in the spec, and had also done some preliminary test and analysis, so the final tuning process was just a matter of tightening and tweaking," Dillon said. Time delay was established with one of the primary end zone arrays serving as point zero, or the reference point to which every other bowl loudspeaker was set.
"One of the most notable things about the design is that energy is kept off the field to a large degree. In fact, we've received compliments on how quiet it is down there," Davis said. "The crowd is normally at about 85 dB with 103 dB peaks. As a result, we run the system at 92 dB to 95 dB most of the time, and then just bring it up when necessary. At any working level, we've found the system to be highly coherent and intelligible, so the primary performance criteria has been met and exceeded."
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