Distributed System At Detroit's Comerica Park

Located within the grid of downtown Detroit, 42,000-seat Comerica Park has emerged as the latest standard bearer in the ongoing paradigm shift of sporting venues, where patrons are provided with a total entertainment experience as opposed to simply a place to see the home team's contests.

An important facet in the entertainment quotient is a modern sound system designed by Wrightson Johnson Haddon & Williams (WJHW) of Dallas. Ron Baker of WJHW proposed a distributed system, including more than 100 EAW, Renkus-Heinz and JBL loudspeakers mounted throughout the main grandstand and outfield seating sections.

Nestled within the grid of downtown Detroit, Comerica Park features a distributed sound system devised by WJHW and installed by SoundCom and KLA Labs.

Loads of Crown amps, divided among two rooms, drive all loudspeakers at Comerica Park. SoundCom did an impressive amount of pre-fabrication of the racks to insure the quickest installation time possible.

"Music and sound effects are playing an increasing role in the desire to offer an enhanced entertainment experience," Baker explains. "At the same time, intelligibility for announcements is always at a premium. A distributed system allows you to fully meet both of these criteria." In addition, distributed systems offer fairly short throw distances from the loudspeakers to the audience, meaning that sound pressure levels are kept relatively low, minimizing potential for meaningful reflections. And it has become a more common practice to arrange these types of systems into zones which can simply be de-activated at the control position to prevent output in empty regions, eliminating additional stray reverberant energy.

System installation, as well as custom engineering services, was handled by two leading firms, KLA Laboratories of Dearborn, MI, and Sound Com Corporation of Cleveland. (KLA has served as the sound and communications contractor for the Tigers since the 1940s.) Sound Com pre-assembled and tested all electonic equipment racks at their Cleveland offices prior to transferring them to the ballpark for final installation.


Don O'Bryan of KLA Labs at the system's host computer in the control room.

"This forward planning, which is standard procedure for us anyway, proved especially fortuitous on this project," says Sound Com's Simon Davis. "By the time the stadium's rack rooms were complete, we only had a week or so to land, load, wire and power the racks."

All loudspeakers are driven by Crown power amplifiers, primarily several models from the Macro-Tech Series, with the MA-2402 being most predominant. Crown Com-Tech Series

handle all 70-volt loudspeakers, including ceiling loudspeakers installed in the concourses and rest rooms. Two rooms house the amplifiers, one located on a lower level behind right field, the other adjacent to the system control position located at the midpoint of the suite level.

The amplifiers also fostered the application of Crown P.I.P- USP2 modules. Plugging into the rear of each amplifier, the USP2 modules offer 24-bit processing, including eight independent, fully adjustable filters per channel, including second-order parametric EQ, first-through fourth-order crossover, and second-order shelving. In addition, the modules offer other features which contributed to the success of this project, such as signal delay and load monitoring. And, incorporating Crown’s Smart Amp feature set, they allow the system operators to fully evaluate the status of several key performance factors of every amplifier.

Sound Com established a network to access the USP2 cards, linking them to a host PC loaded with Crown IQ For Windows v4.1 control software posted at the back of the control room. From there, the system operation staff has the ability to evaluate and verify the performance of all amplifiers, either individually or as groups. However, they are not given access to more crucial functions, such as processing settings and gain control, which are password protected.

"We want them to be able to conveniently see the system and be able to tell quickly if there's a problem," Baker explains. "However, it's imperative to avoid any impact on the delicate balance that's required to make a distributed system work. Even slight changes can snowball incrementally, and if one section is out of balance, it can ruin the performance of the entire system."

The host PC also interfaces with three BSS Soundweb DSP units that are rack-mounted in the control room that supply processing and routing to the various 70-volt systems throughout the facility, with operators given a choice of four program sources that can be assigned to systems serving specific levels of the facility. This is achieved via BSS interface software offering simple point and click operation along with the ability to store presets of common configurations.