Sounding off for sports A sound system for the Super Bowl involves not just sound, but speed and expertise.

After our involvement at Super Bowl XXIX in Miami, Jerry Anderson, architect for the NFL and Super Bowl XXX, called us for Super Bowl XXX. We provided

Sounding off for sportsA sound system for the Super Bowl involves not just sound, but speed and expertise.

Nov 20, 1996 12:00 PM, Michael BradleyBradley is with Chambers Electronic Communications, Phoenix, AZ.

After our involvement at Super Bowl XXIX in Miami, Jerry Anderson, architect for the NFL and Super Bowl XXX, called us for Super Bowl XXX. We provided a study of the existing project and a facility impact statement for the sound-system renovation of the sound systems to accommodate Super Bowl XXX.

In the impact statement, we examined the renovation based on a distributed sound system similar to those recently installed in the new Comiskey Park, Oriole Park at Camden Yards, Anaheim Stadium and those proposed for the Arizona Diamondbacks, the Tampa Bay Devil Rays and the Milwaukee Brewers. I also evaluated a central cluster approach and decided it was the one the University should follow based on the balance between the cost and complexity.

The original sound system in the stadium consisted of a central cluster located on top of the International Collegiate Athletics (ICA) building and delayed loudspeakers on the loge level below the cluster covering the loge level seats, which were adjacent to the ICA building.

The configuration of the stadium overhangs caused insufficient coverage to seats both in the loge level above the main stadium bowl and in the lower stadium bowl underneath the loge level seats. The overhang of the loge level above the bowl was so extreme that one could only see the third floor of the ICA building, while the loudspeaker system was located on the penthouse level above the sixth floor. 98 loudspeakers separately zoned in pairs provided the appropriate coverage to the main bowl and loge level seating areas not covered by the central loudspeaker cluster position.

One of the great hardships of the project was the construction time schedule, between Oct. 13, 1995 and Dec. 25, 1995, during which all renovation work had to be substantially completed. Another big problem was the continued operation of the existing sound system to support the Arizona State and NFL Cardinals home games.

To accommodate continued operation of the stadium during renovation, the existing loudspeaker cluster was disconnected from its center position and moved across the roof to the west, with extended loudspeaker cabling to the rack equipment below. Only minor degradation of the sound was observed in the southeastern corner of the stadium, unobserved by the patrons.

The site studies of the project's structural and electrical systems confirmed existing roof conditions, structural connection points and conduit routing throughout the ICA building and stadium. After our design was complete, it was released for competitive bid by contractors throughout the United States.

The loudspeaker system consists of 12 inch (305 mm) drivers, mid-range horns and high-frequency horns. The devices are divided into six separate frequency ranges to maintain directionality of the loudspeaker system down to 100 Hz. The low-frequency loudspeakers were JBL custom enclosures consisting of three 12 inch (305 mm) drivers per cabinet. The cabinets were stacked three high in eight separate vertical columns, four on each side of the mid-frequency and high-frequency horn array.

The loudspeakers were individually powered using unique power amplifiers for each symmetrically similar driver, with the frequency range of each loudspeaker determined by the physical location of the loudspeaker in the array. Based on recent papers by Jefferson Harrell and Elmer Hixson, the bandwidth of each loudspeaker was limited to minimize multiple vertical lobes common to a multiple driver array. The complete array was designed to avoid multiple-lobe radiation by limiting the response of each driver to a frequency range one octave below the first calculated vertical lobe frequency. This ensured consistent directionality of the array down to approximately 100 Hz.

The directionality of the array was surprising in that normal conversations could occur inside the cluster enclosure behind the loudspeakers during the reinforcement process without hardship.

The Peavey MediaMatrix system was the only cost-effective solution to this array technology based on the quantity of delay and crossover filter requirements of the array. Each of the six loudspeaker cluster frequency ranges were separately analyzed in the stadium, with all frequencies aligned to obtain consistent signal alignment at the 50 yard line.

After adjustment of the central cluster, we provided adjustment of the delays serving the under-deck loudspeakers and balanced the spectrum of these loudspeakers to provide continuous sound quality and coverage to all patron seats for the first time since the upper deck was built.

The south end-zone was augmented by eight full-range enclosures directed down from the cluster to the seats directly below the cluster. This system provided extended coverage to the southeastern and southwestern corners of the stadium to ensure even coverage in the crossover region between the south end-zone loudspeakers and the main stadium system.

The system was beta tested during the Christmas Day NFL game between the Cardinals and the Cowboys. The Cardinals, the ASU staff and Larry Estrin of Best Audio worked together to properly trim the system and balance it to compensate for the varying crowd noise levels throughout the stadium.

The central cluster design gave consistent frequency response to all patrons in the stadium, with minimum impact on the surrounding community. The effectiveness of the design allows more effective implementation of central cluster systems in noise-sensitive communities. PMK would like to compliment Terry Beier of the ASU staff, Larry Estrin of Best Audio and Kim Tollefsen, formerly of Chambers, for their efforts towards the success of this project.

Every January, millions, if not hundreds of millions, of people are glued in front of their television sets to watch the match up between the American Football Conference (AFC) champion and the National Football Conference (NFC) champion. They're watching the Super Bowl. In 1996, Super Bowl XXX came to Tempe, AZ, and was the most watched television event in history.

It was the 1993 Super Bowl that was originally to appear in Tempe, but NFL owners changed the venue once they discovered that Arizona did not celebrate a paid Martin Luther King holiday for state workers. After Arizona voters approved the holiday, the NFL reconsidered, and Super Bowl XXX came to Tempe.

The game was played at the 75,000-seat Sun Devil Stadium on the Arizona State University campus, home to the ASU Sun Devils and NFL Arizona Cardinal football teams.

Because Sun Devil Stadium is a college stadium, the NFL came to Tempe with its checkbook aimed toward significant improvements to bring the stadium as close as practical to NFL standards. In addition to the typical Super Bowl preparations, the NFL insisted upon significantly increasing the stadium lighting, replacing the grass field and installing a new sound system.

Because ASU owned the facility, the NFL turned over control of the lighting and sound system projects to the University, which became responsible for procurement and project management. The university hired Christopher "Topper" Sowden of Pelton Marsh Kinsella Consulting, Dallas, to design the new sound-reinforcement system. The NFL hired Larry Estrin of Best Audio in Van Nuys, CA, to look out for the NFL's interests. Chambers Electronic Communications of Phoenix provided and installed the new sound system. D.L. Withers Construction, Phoenix, managed the project, provided all construction of the superstructure and contracted with Wilson Electric of Scottsdale, AZ, to provide the conduit and fulfill all of the electrical requirements.

Although the stadium had tripled in size, the original system had remained almost unchanged since its installation in the mid 1970s by Chambers Communications. On the roof of the south end-zone athletic building, the original multicellular horns and bass horns were getting tired and could not keep up with the big-event needs of the NFL. The loge seating area surrounding the entire stadium was served by a combination of Atlas PA horns and Bose 102 loudspeakers that had been installed over the years in response to complaints from season ticket holders. Concourses, concession areas and restrooms had no sound. The skyboxes housing the press and the sound booth were built eight years earlier when the Arizona Cardinals moved to Tempe.

The consultant settled on keeping a single point cluster on the south end-zone building, replacing all loge loudspeakers and adding loudspeakers under the seating overhangs and to all concourses, concession areas and restrooms. The systems Chambers Communications had installed in the skyboxes were left untouched except for sound booth renovation. For purposes of keeping the cluster amplification close to the drivers, PMK designed a new building to house the loudspeakers and electronics on top of the athletic building. This structure would be several times larger than the original cluster, and the rack room built behind the cluster would need to have a large air conditioning system to help the amplifiers compete with the hot Arizona sun.

Miracles still happenAs with most renovation projects of this magnitude, the time frame for the contractors to complete the project was far less than ideal. By the time the negotiations between the NFL and the University were completed, the design was finalized and the contract was awarded, only 56 days remained before the new system would be used for the "Monday Night Football" game between the Dallas Cowboys and Arizona Cardinals on Christmas night. To make matters worse, both the Cardinals and the Sun Devils had several home games scheduled in the stadium during construction. The system had to be finished to host the Christmas night NFL game, the Fiesta Bowl National Championship game on Jan. 2 and the Super Bowl on Jan. 28.

The old system would have to remain in operation while the new system was under construction. Because the old amplification was in the basement of the athletic building, Chambers Communications saw that if the old cluster could be moved to the side on the roof, the system could be re-wired and kept in operation with a minimal effect on the performance.

Fortunately, Arizona experiences few rainy days, and snow and cold weather are only found in dreams. Once construction began, only minor delays cropped up over the owner's decision making and approvals. During the design phase, the consultant told JBL, a Super Bowl sponsor, which products would be used, so long-lead products would be in stock. Using Microsoft Project, Chambers designed a detailed schedule with events and milestones clearly indicated and agreed upon by all parties. This tool became an important part of the weekly project meetings and facilitated problem solving and cooperation.

Rock and rollOne major drawback to the old system was created when the loudspeakers were moved in 1988 from a score board to the roof of the new athletic building. The 5,000 bleacher seats under the shadow of the six-story building never had direct sound from the cluster. Building the new cluster cantilevered over the edge of the building solved this problem.

Eight custom JBL weatherproof loudspeaker systems were installed under the overhang, providing sound directed at the south end-zone bleachers and the inside corners of the stadium adjacent to the athletic building. The ticket holders in these seats instantly went from no sound to the best sound in the entire stadium. They responded to the new system during the Christmas night game by spending most of the game on their feet, dancing.

Although college football uses a live marching band, the NFL plays recorded music throughout the game. The new sound system had to be able to really rock and roll to keep up with the expectations of the NFL and the fans. Commercials and video announcements are also played through the system while spectators watch a video screen and television sets. NFL games are no longer just about football, they are an event, one produced at a professional level.

The main JBL cluster is a three-way system covering about 95% of the seating area. New JBL Control One loudspeakers were mounted throughout the loge and under overhangs of the upper and lower decks, providing delayed fill of the main program. Control One loudspeakers and 8 inch (203 mm) loudspeakers were mounted in all concourses, concession areas and restrooms to provide program material from the live radio broadcast of the game. No matter where you go in the stadium, you are never out of touch with the game.

The system is powered by 55 kW of amplification. Crown CT series amplifiers, each on a separate 20 A circuit, are connected to the cluster and all of the 70 V loudspeakers with THWN wire. A new power distribution and grounding system was installed to accommodate the power requirements of the amplifier room.

Digital signal processingThe Peavey MediaMatrix provides the signal distribution, multiple delays, signal compression and parametric equalization. The flexibility of the MediaMatrix system saved a tremendous amount of wiring, installation and tuning time. The system was originally set up and tuned by the consultant for the "Monday Night Football" game and the Fiesta Bowl. Once the Fiesta Bowl was over, the NFL took over the stadium.

To accommodate the needs and requests of the NFL, Chambers Communications created a second setup and tuning in the MediaMatrix computer; after the Super Bowl, it was replaced in the computer by the original set up.

Chambers Communications audio engineer Steve Rosendahl was very impressed by the ease of programming the Me-diaMatrix and the drop and click method of building the signal chain on the computer screen. Because this was Chambers' first experience with the MediaMatrix, the reliability of the program was an issue, but no programming bugs or interface problems came up during the installation and set up.

A simple Windows-based local area network is between the electronic equipment room and the sound booth; the booth's computer terminal can control the MediaMatrix system. The operator is provided with limited access to programming changes to accommodate changing crowd conditions and special events.

The sound booth was also equipped with an AMX Access control system, including a touchscreen panel, mainly used to control the power up sequence of the distant racks.

To accommodate the NFL's audio playback requirements, a 360 Systems instant replay system was installed. The replay system provides digital memory for up to four hours of music or sound effects that can be instantly recalled by the operator by pushing assigned buttons on the console face. For the Super Bowl, Best Audio provided two additional instant replay systems, providing hundreds of possible music selections and sound effects.

The renovation of the sound booth gave the stadium a new Soundcraft Mixer, ADC patchbays and new announcer microphones.

To increase the skybox capacity for the Super Bowl, the NFL took over the fifth and sixth floors of the south end-zone athletic building, displacing coaches and classrooms. Special booths were constructed in front of the windows. Chambers Communications provided sound to all of the temporary booths with custom selector switches at each booth position, allowing participants to choose from a variety of program options, including the broadcast.

Game dayChambers Communications' installation and engineering crews put in plenty of long hours for this event. Technicians Ron Klaus and Brad Hayes supervised the installation crews, dividing the work among the field wiring, sound booth renovations, cluster fabrication and amplifier rack fabrication. Coordination between the electrical contractor and general contractor was critical to completing the project successfully in only 56 days.

The dress rehearsal for the Super Bowl game became the Christmas night NFL "Monday Night Football" game. The system performed magnificently. Although a single point cluster is not as desirable as a more expensive distributed system, the announcements were clear and intelligible at every seat in the stadium, and the music was full range without creating discomfort. The only concern arose over feedback through the field referee microphone; this was overcome when Chambers Communications installed a dedicated one-third octave equalizer and then experimented with various adjustments.

Overall, the system received great reviews from the NFL, the University and the fans. Project manager Kim Tollefsen and George Lind, Chambers Communications' vice president of operations, were pleased that the project stayed on schedule. Because of the NFL's generosity, Sun Devil Stadium is now equipped with a state-of-the-art sound system that rivals any professional NFL stadium.

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