Broader Goals
The arena system needed to meet two often disparate goals: meet public address requirements for sporting events and other general uses as well as deliver true full-range dynamic performance for concerts, convocations, theatrical productions, and so on. Further, it needed to be flexible – not just anchored to one position and also capable of being configured in multiple ways.
“The university staff was excellent in defining the broader goals to be achieved, and communicated well their ideas about flexibility and connectivity,” Johnson notes. “They’re great to work with and very open-minded about the concepts we suggested about where we wanted to take this.”
After some investigation, the sound team came to one inescapable conclusion: dual systems would be necessary to fully meet the vision for the project.
One would incorporate concert line arrays; the other, distributed loudspeakers to cover all seats in the arena bowl. Yet while this involved two complete sets of “racks and stacks” (amplifiers and loudspeakers), most of the rest could be accomplished with shared components and infrastructure.
It started with a digital backbone, and with audio distributed on a local area network where it could be accessed at multiple points not only in the arena, but also in the greater facility. Johnson has deployed CobraNet successfully on several projects in the past and felt it would be an optimum solution here as well.
“CobraNet is stable and proven, really almost a legacy technology at this point, which is a good thing when you want to guarantee success,” Johnson explains. “We also wanted to avoid copper wire for signal transport as much as possible, given the size of the venue, the expense it would incur, and to avoid the EMI (electromagnetic interference) problems that can happen with huge copper cable runs in venues and systems of this scope.”
Miles of cable trays running throughout the outlying areas of the facility accommodated Cat-5e cabling runs needed for this audio distribution system. In addition, going with Cat-5e made for an easier time in routing cable within the existing infrastructure.
There are two bundles on the Cobra- Net network. One is the drive line from the input of the front of house console to the system’s overall digital signal processing (also networked), and the other goes from the processing to Whirlwind CO2a 2-channel output modules in the sky box lounge and ticket booth, both of which receive a matrix mix stereo feed.
“As these types of applications go, this one is pretty light, but we have plenty of capacity in this network,” Johnson says.
“Plus it is expandable for any future need, so anywhere we want to add an audio or a submix feed, it’s essentially a matter of adding a Cat-5e cable and running it where it needs to go.”