Tech Focus: Digital Audio Networking, Part 3 — Hard Rock Stadium Sets a New Benchmark
The Miami Dolphins’ home integrates venue sound on a converged network
Networked audio in sports venues has seemed a fast-track proposition in recent years, but the reality is that digital venue sound remains largely segregated from a venue’s network infrastructure. That’s mainly a function of the entrenched nature of IT culture, which, to some extent, continues to view networked audio as a bit of a digital interloper.
Renamed Hard Rock Stadium last August, the Miami Dolphins’ home looks to create a template for venue sound on a converged network. A system designed and implemented jointly by the Dolphins’ IT and broadcast team, led by Tery Howard, and A/V systems integrator Diversified, is what Pete O’Neil, director, engineering, Diversified, calls “a truly” converged network. “We built the network infrastructure [for audio] off of the core switch infrastructure that lives in the stadium’s data center. That’s unique in sports venues at this point in time.”
The stadium hosts a 20-GB fully redundant fiber-linked network back to the cores, providing enough bandwidth to accommodate all audio requirements, including bowl sound and paging and emergency-notification systems, on separate channels but on the same broadband network infrastructure as other data streams, such as the venue’s IPTV and point-of-sale systems.
“It’s a paradigm shift in that the audio is tied to the data center, along with the other venue networks, instead of on a separate network infrastructure,” O’Neil explains. “And it’s end to end: when the network fiber comes into an amplifier–rack-room location, it comes to the switches as digital, and the signal is then sent the last few feet to the amps over IP, not as analog over copper.”
The Hard Rock Stadium is a minor Babel of networking protocols. The audio portion of the network uses Dante’s networking protocols, which O’Neil calls the “glue” that interfaces with other proprietary network protocols. For instance, the venue’s Yamaha CL5 FOH console is linked via a QSC Dante card to the QSC Q-LAN network, the signal transported over the converged network on fiber via a10-GB switch infrastructure. The Q-LAN network goes directly to the audio system’s amplifiers. In another instance, the Evertz router is linked via MADI to the Dante network and back to the Q-SYS network via a QSC Dante input card. It can get complex and underscores audio’s still evolving place in large-scale network applications.
Other proprietary audio-networking protocols that might be encountered include Harman Pro’s Hi-Q-Net and Riedel’s RockNet.
“While Q-LAN is more universal because it incorporates AES67, Dante is kind of like the glue we use to hold them all together,” O’Neil explains, “because most [pro-audio] manufacturers have adopted Dante into their products. And, when we need to interface with video-control data, we use a Dante bridge via MADI.”
Because of that kind of emergent status, some IT managers prefer to keep audio segregated on their networks. O’Neil says that the Dolphins’ IT staff, headed by Howard and Director of Broadcast Operations Tomas Ruiz, instead sought to integrate audio on an equal basis with the rest of the stadium’s network traffic.
It required some extra effort. O’Neil notes that Cisco’s 3850 switch, which was introduced in 2015, as planning for the network got under way, turned out to have latency issues with audio, partly because of the enormous amount of other data traffic on the converged network. The IT team’s strong relationship with Cisco resulted in development of a firmware update that specifically addressed that issue. In fact, says O’Neil, the update is nicknamed “Miami.”
“They had the clout with Cisco to get that addressed,” he observes. “That was critical considering how [deeply] audio was going to be integrated into this network.”
The Hard Rock Stadium has significant benefits to show for the chances the team took. O’Neil cites flexibility (any input source can be added to the network at any point via a switch), signal quality (audio remains digital until the output stage of the amplifiers, just before the speakers, without any artifact- or latency-inducing conversions), scalability (the sound system can be expanded with the addition of new endpoints, the only limit being the network’s available bandwidth), and system-wide redundancy, which increases reliability.
An Inflection Point
According to Justo Gutierrez, director, AV sound/sports and live events, Diversified, the Hard Rock Stadium’s networked audio marks an inflection point for sports-venue sound. “We’ve seen audio networking over IP for a decade now, but we haven’t seen it truly converged as it is here,” he says. “The audio really lives on the Dolphins’ network, and they can access it from any IDF closet in the venue. That’s rare for networked audio in general, and it’s a big moment for sports-venue sound. To make that happen, it needed an IT team that was willing to take on that challenge and an integrator that understands and respects the IP side of the equation. That happened here.”
Martin Barbour is product manager for installed sound at QSC, whose Q-SYS network is used in the Hard Rock Stadium’s audio infrastructure, as well as the co-chair of the marketing working group at the Media Networking Alliance (MNA), the industry trade group that developed and markets the AES67 protocol-bridging technology. Regardless of which hat he’s wearing at any given moment, he is happy to see the abundance of audio-networking protocols able now to interact and connect together to an extent only aspirational just a few years ago.
“The handwriting has been on the wall and has been for some time now,” he says of networked audio’s inevitability. “The new-generation networking protocols have learned how to play nicely with the IT world.”
This comprehensive approach to networked audio is being tentatively applied to a few other which venues that Diversified is working on, including Colorado State University’s football stadium and, set to open this year, Detroit’s Little Caesars Arena, home of the NBA Pistons and the NHL Red Wings. However, Gutierrez emphasizes, it’s very much the exception rather than the rule.
“We’re still looking at limiting the exposure of the audio network to the venue’s network most of the time,” he says. “Instead of 500 channels on a fully converged network, we still look to segregate that audio on its own closed-loop network. A fully converged network is the ultimate goal, and it’s achievable. For now, we’re still on our own 20-yard line.”