HBO Boxing Has Noise on the Ropes With Networked Fiber Audio Transport

Fiber continues its penetration into audio transport for sports broadcasting. After NFL and, most recently, the Summer Olympics shows relied heavily on fiber cabling, boxing is the next to go that way.

According to Randy Flick, long-time A1 for HBO’s boxing shows, the NEP SS17 truck, which has been the first-call remote-production vehicle for HBO’s boxing events, has just wrapped up a year-long conversion from copper to fiber for audio.

At the heart of the upgrade are six Lance Design ADX-2400 audio-distribution units — three at ringside and one each in the locker room, house AV, and RF operations center. They serve as the digital hubs for deployment of eight Lance Design ADX-120 and four ADX-140 field announce units.

The ADX-120 announce boxes have two mic inputs, two stereo IFBs, one two-channel RTS partyline, and two talkback outputs and enable up to eight announcers at ringside. The ADX-140 is a 1RU version of the ADX-120 but has four mic inputs and no talkback outputs and is used to ship the ringside effects mics used back to the truck.

Each of the ADX-2400 units can handle up to four of these field boxes, which take in microphones set up throughout the venue. These include effects mics such as the Sennheiser HME26 electret condensers used for the announcer microphones, the Sennheiser 816 shotguns mounted on fish poles at the red and blue corners of the ring, and the 416 shotguns that pick up ambient effects sounds over the ring and from neutral corners.

Flick says the conversion process began in January 2013 after he and HBO Boxing Production Manager Jason Cohen agreed that transitioning to fiber cabling would significantly streamline workflow and signal transport. In fact, it reduced the truck’s copper-cabling infrastructure from 15 runs of DT-12 copper to four runs, and Flick says that will likely go down to three later this year. “And those DT-12s are used only for backup,” he adds, “so the reality is that the shows are now all-digital for audio.”

The Lance Design boxes use CobraNet as a network between the stage boxes and the truck, with all cabling run on fiber or Cat 5e cabling over Ethernet. The network uses a combination of HP Ethernet switches at the truck and in the venue. After reaching the stage boxes, all the audio is brought back to the truck as digital and stays that way as it goes into the truck’s Calrec Sigma console. A separate, analog feed is sent to the truck’s RTS ADAM intercom system.

“We’re going analog to digital in less than 10 ft. of cable, versus 1,000 ft. of copper in the field coming back to the truck using DT-12,” Flick calculates. “And it’s then when you realize how quiet it is with an all-digital path. Analog was vulnerable to adding crosstalk and more chances for noise in the form of hums and buzzes.”

Viewers will get to hear everything but the noise on the next show, when Julio Cesar Chavez Jr. fights Brian Vera at the Alamo Dome in San Antonio on March 1.