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There is a threshold when simplicity gives way to complexity, when a plug-and-play network has to become a managed network.
Networked audio is the closest thing pro audio has had to a true stealth proposition. The idea of putting digital audio onto a local area network has been around for some time, in the form of systems like CobraNet and EtherSound, but the details of those earlier systems tended to be opaque to most viewing them from the purely audio perspective. They were very much IT entities, made that much more mysterious and Delphic by their times, more than two decades ago, before streaming had become as commonplace as it is today.
Recent entries in the networked audio category are far simpler and direct, such as QSC's Q-Sys, Audio-Video Bridging (AVB) and perhaps the biggest success story in pro audio since the CD, the omnipresent Dante system, whose sheer pervasiveness has made it a default character in virtually any media technology narrative, including this one.
EASY TO USE, BUT BE CAREFUL
The major difference that this new generation of audio networking platforms has achieved is true plug-and-play operability. At the small-venue level, this has been revolutionary, allowing small- and mid-sized churches to cobble together basic systems that take audio from a stage box to a console and to the amplifiers using a few Cat-5 cables. But the implications for larger churches are even more significant, though also more complex. The convergence of audio and IT has a lot of potential benefits for houses of worship, but it comes with its own set of challenges and costs.
Matt Wentz, audio systems engineer at Willow Creek Community Church in Chicagoland, says he hasn't found a negative yet to the transition to networked audio that's now implemented in the church's four main venues, and will be extended to a half-dozen smaller ones in the future. These spaces, including the 7,200-seat main sanctuary and the Activity Center, a large, multi-purpose space used for worship, meetings, educational classes and live performances, operate as stand-alone facilities, each with its own networked PA system comprising Yamaha CL or M7 series consoles and RIO series I/O stage boxes, all of which are Dante-enabled. Utilizing an Auvitran AVB central router, each of these venues can share content in real time with each other; thus, services in one location can be heard, without any significant latency, in any of the others, essentially creating instant overflow spaces.
Wentz enumerates the upsides to networked audio: far fewer cables, longer runs between endpoints with no loss of signal, high channel counts, lower overall costs, simple and quick system changes whether it's reassigning one channel or reconfiguring an entire system. And, he adds, simplicity of operation—up to a point, anyway. There is a threshold, and it will vary from situation to situation, when simplicity gives way to complexity, when a plug-and-play network has to become a managed network.
“You can suddenly find yourself in over your head if you're not aware of all the ins and outs of networking at a certain scale,” he cautions. “If you're doing multicast streams you've got to be concerned with issues like quality of service,” usually expressed as “QoS” and which relate to measurements of service parameters including error rates, bit rate, throughput, transmission delay, availability, and jitter. “The knowledge base you need for this goes up considerably at that point.”
"Our policy is to always do everything on Monday. That way, you have all week to deal with it if something goes wrong."
Chuck Mitchell
Owner, Technology of the Arts, Cypress, CA.
NOT FOR EVERYONE
The idea of a knowledge threshold is heard often among IT-savvy technical workers in houses of worship. Dylan Mills, a project engineer at AV systems integrator Diversified Systems in the San Francisco Bay area, says while putting audio on a network can offer churches I/O location flexibility and less costly expansion capability (need to add more speakers? Run just one cable and only as far as the nearest network switch), the IT skills needed to install and terminate that switch and manage network traffic aren't as readily available as more conventional pro audio skills.
“Networked audio isn't necessarily for every church, and it does work best when a church has someone on staff or available who understands Ethernet networking,” Mills says. “These aren't the same knowledge bases as with analog or even digital audio. This is IT.”
Most in IT professions would recommend that their clients establish a separate LAN or V-LAN for their audio, but that's not always feasible in the lean sort of enterprise that a church can be. “You need a certain amount of bandwidth to keep the audio-data packets properly timed and synched,” says Mills. “Having that data share a [converged network] with other data can be tricky. That really requires an IT professional.” In fact, he adds, small churches that are looking at networked audio simply because it's the “next big thing” ought to consider sticking with their current infrastructure, as long as it's sufficient for their current needs. “Traditional infrastructure is going to be with us for a long time,” he notes.
OPTIONS
Dante is an authentic juggernaut, although other options for audio networking are available and can be quite viable. Mills uses Dante but has also had good experiences with Q-Sys when a dedicated LAN is available. He will also use Audio-Video Bridging (AVB), a standards-based transfer format, when he wants to use certain pieces of equipment, such as a PreSonus mixer/stagebox combination that's compatible with the switches that have been certified by the AVnu Alliance, the trade body managing AVB. In fact, he says, he might use these types of products more often, were it not for the very slow pace at which the AVnu Alliance has been announcing its product certifications.
Wentz is sold on Dante but says he's keeping an eye on AVB, too, although he says he's also disappointed in the length of time it's taking for certified products to get to the market.
The older networking options, like CobraNet, have steadily declined in use and will likely continue to do so, with users citing latency and transmission-scheduling issues with them. But this isn't to say that Dante doesn't have its own issues. Mills points out that the proliferation of Dante-licensed manufacturers—there are over 250 of them now—means that there are plenty of products to choose from, but also that not every manufacturer will implement firmware updates immediately as they become available, creating some operation disparities in the field. He cites occasions when mixers from different manufacturers, all of which were Dante licensees, were hit by operational problems that were eventually traced to firmware issues, but not before phone calls to those manufacturers resulted in them apportioning blame to each other. “Sometimes it can be tricky to get a number of devices from different manufacturers to play nice with each other on the same network,” he says.
Chuck Mitchell, owner of system designer/integrator Technology of the Arts in Cypress, Calif., says the unpredictability of software and firmware updates, from Dante and manufacturers of Dante-enabled devices, is a typical IT-centric bugaboo, but it will be new to most AV-ers.
Another sore point could be the need to make sure that all of the switches on the network are properly sync'd to both the primary and backup clocks, and that the clocking is solid. (Clocking uses the IEEE 802.1AS protocol and is critical to ensuring that data packets arrive when and in the order they're supposed to. Within the 802.1AS network timing domain there is a single device called the grandmaster that provides a master timing signal. All other devices synchronize their clocks with the grandmaster.) “One of the issues that has to be watched for is that updating firmware can also change how a device deals with the clock,” says Mitchell. Troubleshooting the problems that result from that can be time-consuming and frustrating, since it's not always immediately apparent where to look.
With dozens of switches and devices on a single network, trying to search globally for updates is virtually impossible, so Jason Vandergrift, programmer at TechArts, as Technology of the Arts is also known, says it's best to look for patches that address specific issues as they arise. “With Dante, for instance, we don't update the firmware unless there's a known issue,” he says.
The most critical best practice that Mitchell can recommend for those embarking down the networked audio road? “Our policy is to always do everything on Monday,” he says. “That way, you have all week to deal with it if something goes wrong.”
Networked audio's uptake has been rapid in some market sectors, such as touring sound, where it reduces the weight of traveling systems by hundreds of pounds of copper cabling. In the church market, it seems to be following a familiar script, with the largest churches adopting the concept first, thanks to their greater access to knowledgeable staff. As costs come down and the promise of true plug-and-play operability becomes manifest, networked sound will likely become the norm in a few years, with systems renovations offering the opportunities to implement it. In that regard, networked audio's arc will follow that of digital audio in general.
