Tech Focus: Bringing Broadcast Audio Inside Poses Acoustical Challenges for Venues

At the NBA All-Star Game in February, Turner Sports went deeper into a concept that it had been working on for two years, a concept that’s likely to appear more often at other extended sports-event shows. Starting with the 2014 All-Star Game, Turner has sent elements of some games’ broadcast audio into the venue through the PA system.

This year, for the Saturday events preceding the All-Star Game on Sunday, the live and broadcast components were produced as a single integrated proposition for the first time. Much of what fans in the stands heard in the venues, from music to announcers to certain sound effects, was also heard on the air, and vice versa.

During the regular season, the network had been collaborating with the league and the venues’ live-sound-system operators, as well as with third-party sound-reinforcement providers, to improve the fan experience for both live and broadcast. They worked on such aspects as system tuning, equalization, frequency response, pattern coverage, and sound-pressure level (SPL) in an effort to optimize the sound in the arena and, by extension, the audio on television: for instance, by reducing acoustical reflections that reduce the intelligibility of announcements.

Tom Sahara, VP, operations and technology, Turner Sports, noted at the time that the unified experience required “a huge effort to make it all into one big show. … In the past,” he added, “people at the events and viewers at home would be having dramatically different experiences. This year, … the experience is going to be seamless.”

Outside Sound
Mark Dittmar, VP, design and engineering, Firehouse Productions, a sound-reinforcement provider that handled live sound for both the 2014 and 2015 All-Star Weekends, says the NBA event has been charting a course closer to what he regularly does with award-show broadcast, such as MTV’s Video Music Awards: creating a unified sound experience for both the venue and the broadcast audiences. There are two keys to being able to do that effectively, he explains: keeping the energy from the PA system tightly focused on the audience seating areas and away from reflective surfaces and keeping the SPL inside the venue within a very tight specification.

The first requirement is addressed by using highly steerable PA-speaker components to avoid feeding sound back into open broadcast microphones, which could cause such artifacts as comb filtering. Both venues used for the 2015 NBA All-Star Weekend events — Madison Square Garden in Manhattan and Barclays Center in Brooklyn — had touring PA-system components installed.

At MSG, Firehouse Productions implemented an audio system comprising four arrays of 15 JBL VTX V25 loudspeakers, plus one array of 10 V25 loudspeakers, all hung from the ceiling around the Garden’s main scoreboard. The system also included 12 VTX G28 ground-stacked subwoofers and 16 Vertec VT4886 subcompact loudspeakers for fills.

At Barclays Center, which hosted the Rising Stars Challenge and Degree Shooting Stars, Firehouse provided six arrays of 15 Vertec VT4889 loudspeakers, plus 16 VT4886 subcompact loudspeakers for fills. The systems were powered by Crown I-Tech amplifiers and were monitored and controlled with JBL’s HiQnet Performance Manager software.

“In our systems design,” Dittmar notes, “we drew a hard line at the edge of the first row of seats. The speakers are so precisely aimed that, if you take one step forward from that line, you’d hear an approximately 20-dB drop in level immediately.”

The second issue, keeping the volume level within the 90 dB specification issued by the NBA, has a basis in physiology. “When the ear hears sustained loud sounds, such as a music performance, it takes the ear some time to recover from that, and, while it’s recovering, it won’t hear softer sounds as well,” Dittmar explains. “If we had Arianna Grande at 105 dB, the [live] audience would have trouble hearing sound effects such as sneaker squeaks later during the game. At 90 dB, their ears recover much faster. As a result, we didn’t need to put those kinds of effects into the PA system.” (However, the lavalier microphone used to capture the swish of the basket is pumped through the PA.)

Included in that 90 dB limit is the output of subwoofers, which are necessary for the hip-hop music closely associated with the sport. Fortunately, most of that output doesn’t get into the broadcast because, Dittmar explains, the broadcast microphones often use high-pass filters set at 80-110 Hz if low-frequency noise, such as that caused by HVAC systems, is an issue; [they] would also effectively screen out the 60-Hz and lower sub frequencies.

Interestingly, although this year’s event involved a larger than usual number of A1s — a total of five, including broadcast A1 Dave Grundtvig, live-entertainment A1 Al Centrella, broadcast-music mixer Jay Vacari for the broadcast sports events and music performances on Turner, and those mixing related shows on ESPN — Dittmar says that this year also saw the adoption of a single set of microphones for the crowd-sound mix for both music and sports.

The integration of such audio elements, along with the league mandate to keep the lid on volume level, made for a complex project but one that Dittmar says resulted in a more coherent outcome for both broadcast and in-venue fans and ultimately will benefit other hybrid events.

“Keeping the volume at a certain level without sacrificing any of the excitement is definitely a challenge, but it also made the overall sound cleaner and tighter,” says Dittmar. “And I’ll take some of that experience back to the entertainment clients that I work with, the music-awards shows.”

As the line between sports and entertainment continues to fade, the separation between the in-venue and home-broadcast experiences is on the way to fading out as well.

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