Tech Focus: Digital Signal Processing and the Plug-in

Things change slowly in the world of live broadcasting. And for good reason: With tens of millions of dollars on the line, an NFL or MLB game is not the time or place to experiment. For instance, the shift to multilayered digital consoles, a transition that took place a decade or more ago in music production and audio postproduction, is still a work in progress in sports.

Change in another aspect of sound for sports may be beginning, even if on a limited basis. Signal processing, particularly basic functions like equalization and dynamics, has typically been addressed either through the use of outboard hardware units like compressors and parametric EQs or through the integration of those functions into the console itself. However, the plug-in — external, third-party software meant to work like highly specific apps for audio recording and mixing —has been a staple in other areas of audio production and may soon have an impact in live sports production.

Cultural Issues
As software, plug-ins are implicitly digital and, as such, had to wait for more of the remote-truck infrastructure to go digital first. Now that that’s taking place, plug-ins also face some resistance from the A1s, who prize reliability and familiarity above all else on a live show. That said, though, they also see the immense sonic possibilities that plug-ins can offer.

“There are some I’d love to be able to use because the possibilities are limitless,” says Dan Bernstein, whose portfolio includes mixes for X Games, ESPN Sunday Night Baseball, and Wimbledon and the French Open on NBC. “But the real limitation is time: On live sports shows, you don’t have the time you need to figure out a new piece of equipment.”

Time works against external processing in another way: latency. Analog processors are often unusable today because of the time it takes to do the A-to-D conversions in addition to the processing time. However, some particularly dense digital processors, like certain plug-ins, also consume a precious millisecond or two in performing their tasks. In the studio, where the sound is the main focus, latency can be addressed via a global system offset. In live situations, where the sound is part of a much larger broadcast-video production, latency is the kiss of death.

“An announcer can tolerate a latency of 2 to 3 ms before it starts driving them crazy in their IFBs, [and] as the latency in their headsets increases, announcers start talking slower and slower,” says Randy Flick, an A1 who mixes HBO’s PPV boxing shows. He notes that the Calrec consoles that are ubiquitous in remote trucks for sports afford A1s most of the basic DSP they need, but, like his colleagues, he’d be happy to have a plug-in option at times: “I know that many mixers would love to have the ability to use EQ or dynamics plug-ins like a Pro Tools rig affords you, but that hasn’t happened yet in mainstream sports mixing.”

A Collateral Niche
Simply put, plug-ins run up against the operational culture of live sports, which tends to rely on tactile interfaces like faders and ballistic meters rather than the virtual interfaces of plug-ins, even though they are remarkably precise at mimicking the hardware.

But at least one major plug-in supplier sees live sports as a potential market, at least as a collateral niche to larger applications, such as live-music mixing. “We have been targeting the live-sound market,” observes Mick Olesh, VP of sales and marketing for Israel-based plug-in manufacturer Waves Audio. “Sports is a part of that market.

The company has been developing and marketing plug-in processors aimed at the live-sound market, achieving what he says is a latency of 1 ms or less, depending on the type of processing. The company also recently adapted its SoundGrid software engine to integrate with DigiGrid, introduced last year, which combines SoundGrid with a MADI interface box from console manufacturer DiGiCo and lets any MADI-enabled audio console connect to it via a Cat 6 cable. The platform allows users to process and play back up to 128 audio channels and asserts latency of 0.8 ms.

Sports mixers won’t need anywhere near that number of plug-ins, but Olesh says this arrangement would make available a handful of specialized ones, such as Waves’ Dugan Automixer, a digitized version of a Dan Dugan Sound Design hardware-based automixer. It uses a proprietary voice-activated processor to control the gains of multiple microphones in real time, reducing noise and comb filtering from adjacent microphones.

(Console suppliers are also incorporating similar types of functionality into their boards as a kind of integrated plug-in. For instance, Calrec last year added its own automatic mixing function to the Bluefin2 signal-processing engine used in its Apollo and Artemis consoles.)

“When it comes to plug-ins for live applications, engineers don’t want toys and bells and whistles, which are fine for the recording studio; they want things that solve problems,” Olesh says. He believes that sports A1s will eventually integrate plug-in products into their workflows once they realize that, operationally, the plug-ins are very similar to the hardware versions they’re used to. “It’s just going to take a while.”