NAB Show Audio: A Tale Of Two Transitions

Television broadcasters attending the 2015 NAB Show, April 11-16, in Las Vegas will find themselves in the midst of two transitions in audio technology that promise profound changes for how they work and the quality of audio they deliver.

The first transition — the migration away from familiar audio accoutrements and workflows to audio over IP — has the potential to lower costs, increase flexibility and make it fast and simple to route audio without reconfiguring patch panels or audio routing switchers.

The second changeover — the passage from 5.1 surround sound as the gold standard for television broadcasting to an immersive, viewer-customizable audio experience as part of ATSC 3.0 — at this point is only a possibility. Yet, the systems under consideration by the Advanced Television Systems Committee for next-gen TV audio will make their mark on the exhibit floor, in private suites and during conference presentations at the NAB Show.

Together, ATSC 3.0 audio and audio over IP are likely to leave TV engineers attending NAB with a new insights into just what is possible when it comes to television sound.

Audio Over IP
“The TV industry is poised for an amazing trajectory of adoption of audio over IP,” says Marty Sacks, VP, The Telos Alliance.

Axia Audio, a division of Telos, came to market in 2003 with Livewire, an audio-over-Ethernet system, after about four years of development, says Sacks. Since then, Telos has sold some 5,500 audio consoles and 60,000 IP-enabled convertors, but mostly to radio broadcasters.

What will be new about audio via IP at the NAB Show is television broadcasters are now ready to take it seriously, Sacks says.

TV engineers who have been on the sidelines watching their radio counterparts deploy audio over IP technology for more than a decade are now satisfied it’s ready for primetime, he says.

Another factor contributing to their growing confidence is AES67, the Audio Engineering Society’s standard for audio over IP.

Adopted in fall 2013, the standard guarantees TV broadcasters a level of interoperability between IP audio systems from competing vendors that previously was unavailable in the IP domain, Sacks says. At NAB, AES67 appears ready to make its biggest splash yet.

AES67 is an audio-over-IP layer 3, or network layer, protocol that can serve as a bridge to transport IP audio packets between AES67-enabled IP audio systems from different vendors that are otherwise incompatible.

“We couldn’t be happier about AES67 and are throwing our full weight behind it,” says Sacks. At NAB, Linear Acoustic, a Telos division, will feature its SDI xNode, which de-embeds two separate SDI inputs and converts the audio to Livewire or AES67 formats.

“Basically, AES67 gives us base line communications between two devices,” says Phil Owens, head of East Coast sales for Wheatstone.

“It allows for common parameters to be set so that boxes can send and receive IP streams and understand them,” he explains.

Those parameters include sample rate, packet size, clock recovery methods and quality of service settings, but not discovery, which is the ability of a device to find out what other devices are on the network, or control, says Owens.

For instance, changing the gain on a mic pre-amp is a control function that is possible via a vertically integrated IP network, such as WheatNet-IP, but not with AES67, he explains.

“You would like to see a world where IP audio and control and discovery can be freely exchanged in an open source-type model,” Owens says. “I think AES67 is really sort of a first step towards that.

“I might sound like a curmudgeon, but I am not putting it down at all. Every journey begins with a first step.”

Owens adds that Wheatstone expects to demonstrate support for AES67 at its NAB Show booth.

Audinate, the company that developed the Dante solution suite for audio over IP in use by 208 OEMs, is getting onboard the AES67 bandwagon as well, says Lee Ellison, company CEO.

The company will support AES67 as a transport option to enable the equipment of its OEMs to bridge to the equipment of third-party vendors that also include the new AES audio-over-IP standard, he says.

“What we see as the market for audio over IP is at the very beginning, and we see AES67 as being just one of the standards Audinate can rely upon,” says Ellison. “We think standards are good things that grow the industry.”

Like Owens, Ellison agrees AES67 is a newly adopted standard and as such not as mature of an audio-over-IP solution as longer-standing IP alternatives for audio transport. Dante, for instance, includes device discovery as well as network monitoring to ascertain statistical and status information, which help synchronize clocks across the network down to +/-1 microsecond.

However, AES67 creates “a wider spectrum of equipment” that can be connected together via IP and therefore will be an important factor in driving the adoption of audio over IP as an alternative to traditional point-to-point methods of audio signal distribution, says Ellison.

It further exposes TV broadcasters to the opportunity to leverage technology developed for the much larger IT marketplace and enjoy the benefits of lower costs, greater bandwidth and more switching flexibility, he adds.

Next-Generation Audio
By time the NAB Show opens in April, more than a month will have passed since ATSC began its technical review of three competing alternatives for the sound system that ultimately will be integrated into its next-generation ATSC 3.0 digital television transmission standard.

Those alternatives — Dolby Atmos from Dolby Laboratories, DTS:X from DTS and MPEG-H, which is being backed by Technicolor, Qualcomm and Fraunhofer — will allow television viewers to experience a more immersive, enveloping audio experience and give them the means to customize how and which program audio is presented to meet individual listening requirements.

(Editor’s note: To learn more about the systems being reviewed, see: Next-Gen Audio Goals: Immersive, Personal.)

On Sunday, April 12, at NAB, ATSC will hold a three-hour tutorial on its next-generation digital television standard beginning at 3 p.m. The chairs of the various ATSC specialist groups at work on different aspects of the standard will present updates on their work, including a review of the ongoing technical evaluation of the three next-gen audio systems, says ATSC President Mark Richer.

Specifically, the audio portion of the program will give TV broadcasters in attendance a look into “a pretty complicated” testing and evaluation process, he says.

On the show floor and in private suites, broadcasters also will be able to get a much closer look at systems.

Dolby will show its Atmos system, which enables moving audio to be placed precisely in 3D space to deliver an immersive audio experience, the company says.

The MPEG-H Audio Alliance will have two booths on the NAB Show floor. Qualcomm’s booth demonstration will revolve around live, higher-order ambisonics, a means of representing a 3D sound field that’s not dependent upon traditional audio channels or dynamic objects.

Fraunhofer will focus its floor demonstrations of MPEG-H on ways the new standard can be integrated today into television stations and networks without disrupting current operations, says Robert Bleidt, division general manager, audio and multimedia for Fraunhofer USA Digital Media Technologies.

“One of our plans is a gradual, staged implementation [of MPEG-H] in TV broadcasters’ plants so they don’t have to change out the whole thing and re-engineer everything to use the new audio codec,” he says.

DTS, which has submitted DTS:X to the ATSC for next-gen TV sound, also will be exhibiting on the show floor. The company, which reportedly plans to make details about the system available this month, did not provide any specifics about its NAB booth demos for this article.

Fade To Black
TV broadcasters attending this year’s NAB Show will find themselves playing parts in a tale of two transitions when it comes to audio.

One, a gradual but steady moving away from traditional point-to-point audio signal routing to a more flexible and affordable audio-over-IP alternative, will open up greater efficiencies and more workflow possibilities to those involved with TV sound.

The other, which ultimately depends on receiving government approval, has the potential to vastly improve how viewers experience TV sound while keeping broadcasters competitive in a changing media landscape where over-the-top distributors do not face the same regulatory hurdles.

While obtaining the go-ahead from the government to deploy ATSC 3.0 with its immersive, customizable audio system may appear to be a daunting obstacle to most TV broadcasters attending the show, at least they can take solace in the fact that a massive effort is underway to make the next-generation TV standard a reality from a technical point of view.

“It’s one heck of a big effort,” Richer says. “There are hundreds of people around the world working on ATSC 3.0, and I’m just amazed every time I go to a meeting, get on a conference call or watch the email go by.

“It’s amazing, and audio is an important part of that.”

This is the latest installment of a special series on emerging tech trends, NAB Hot Topics, that will appear each week leading up to the NAB Show that runs April 11-16 in Las Vegas. Next up on April 2 is Automation, followed by a Tech Roundtable on April 9. Read the earlier installments here.