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WLS ABC7 Chicago uses latest technology for Lights Festival broadcast

The live HD broadcast of Chicago’s 2011 Magnificent Mile Lights Festival by WLS-TV, an ABC-owned TV station, is a challenging event, requiring extensive use of wireless microphones and intercom systems in an RF-intensive outdoor environment.

Performers included Grammy-winning sister duo Mary Mary. Parade grand marshal Mickey Mouse was on hand to illuminate more than one million lights on 200 trees lining Michigan Avenue, officially kicking off Chicago’s holiday season.

This perennially difficult assignment became much easier in 2011 with the use of two new and unique wireless systems: the Shure Axient microphone system with frequency diversity, and the Tempest900 digital intercom from Clear-Com. In addition, the Shure PSM 1000 in-ear wireless was used in point-to-point (P2P) mode to supply audio to the event’s PA system. WLS enlisted the aid of On Stage Audio (OSA) in suburban Wood Dale to supply the equipment.

In beta test but due to ship imminently, Axient is Shure’s state-of-the-art wireless network management system, designed to handle the most crowded RF condition. Its advanced features include extremely tight RF filtering combined with spectrum management, frequency diversity, and remote transmitter control via a wireless data backchannel.

In its first documented use in Chicago, the Clear-Com Tempest900 utilizes patented Frequency Hopping Spread Spectrum (FHSS) technology, continually changing frequencies in the 900MHz band to break through noise and interference while penetrating dense structures to provide reliable communication in demanding RF environments such as Chicago’s Michigan Avenue in the heart of downtown, within line of sight of several DTV broadcast towers.

ABC7’s temporary broadcast site included a “backstage” tech area and nearby dais for three broadcast anchors. It also required wireless signals for street reporter Val Warner on the parade route and the nearby performance stage. Eight channels of Axient were employed, including a handheld and bodypack system for Warner, and a pair of handhelds for Mary Mary.

After the capabilities of Axient were explained to them, WLS audio engineers Lou Sabatini and Mike Cunningham could not pass up using the new Shure system. Sabatini, who handled the broadcast mix, reported, “We got to see firsthand how Axient can detect and prevent a problem before it happens.”

During rehearsal, the system detected interference on one of the anchors’ system. “The display on the receiver turned red to show us the problem,” reports Cunningham, who was responsible for frequency coordination. “It turned out to be interference from an unplanned in-ear system. Axient switched the transmitter and receiver to a safe frequency. That would have been a major panic situation, but Axient handled it seamlessly — detecting the problem, alerting us, and having a safe channel ready to go.”

The team had similar success with the Tempest900. The reach and reliability offered by the Tempest900 systems allowed event coordinators to roam and communicate freely along Michigan Avenue. The system effectively covered a three-city-block span north of the Michigan Avenue Bridge without issues.

“The Tempest900 functioned well, providing reliable communication throughout an extensive area of Michigan Avenue,” says Cunningham. “We simply installed two Tempest900 systems at a single location at the base of the festival route, and that was sufficient to enable clear conversations to occur throughout the course of the event. This installation allowed for faster decision making, shortened response time, and ultimately, more effective collaboration.”

One final piece of new technology was employed to address another vexing issue — getting broadcast audio to the bleachers located across Michigan Avenue from the broadcast position. For this task, OSA senior staff engineer Pete Wiejaczka employed the Shure PSM 1000 personal monitoring system in its point-to-point mode, sending full-range audio to the PA system with no discernible latency or quality loss.

As he says, “The sound quality is excellent, and the PSM 1000’s point-to-point mode allows me to use a Shure UHF-R receiver, which meant I had balanced XLR outputs instead of the mini headphone jack that’s on an in-ear bodypack. It’s a great solution anytime you can’t run cable to the PA system.”

Video from the Nov. 19 live broadcast of the 2011 Magnificent Mile Lights Festival is available on the WLS-TV7 website.