Audio Routers: Smaller, Faster, Maybe Cheaper, Definitely Better

By Dan Daley

Trends in general tend to be less than clearly defined, taking on concrete shape only when seen in the rearview mirror. Not so the biggest trend in audio-router design. “Less than four years ago, you could count on the fingers of one hand the number of manufacturers that had a router that was 512 [I/O] square or bigger,” says Todd Riggs, product manager for large routers at Harris Corp. “But since then, the size of routers has exploded to the point where it’s not uncommon to see 1,024 square in a single frame — and it’s still growing.”

That has been driven by several factors, including the proliferating number of audio channels and sources, the increased interplay between discrete and embedded audio sources, and, not least, the need to optimize space and weight in remote trucks. Taken together, these forces have shaped router design significantly.

“Customers used to have to make a decision between buying for an embedded or a discrete plant environment,” says Riggs. “In response, the trend has been to move what had been the external processing and make it internal within the router.” Not only does that save space, but it also creates a much more flexible proposition for manipulating both embedded and discrete audio sources within the same box. “This eliminates a lot of cable, external racks, power, and heat.”

Another decision is between distributed routing and a centralized matrix, according to Keith Bond, director of product management at QuStream: “A distributed-router approach lets the interfaces be located where they’re needed, and the signals can have longer runs over Cat 5 cabling.”

In terms of the size of matrixes, Mitch Hayden, director of product management for routing and signal management at Grass Valley, points out that the router sector is mimicking the evolution of the OB van. “You’ve got the ‘super trucks,” he says, “and it’s not unusual to see a 1,042-squared matrix in them, down to the smaller mixed-format audio/video routers like our Concerto in smaller trucks.

The increased size and capability of trucks, combined with plant-scale routing matrixes, are a natural response to increasingly complex sports-event broadcasts. “You’ll see 10 ‘super trucks’ at a Super Bowl, but as importantly, you’ll see many of them sharing resources, which is not something you notice at the everyday-type games,” Hayden says. This underscores how the trucks are evolving from mixing entities to more fully formed production environments, a phenomenon that larger and mixed-format routers help support. “In the fixed plant, they’re trying to figure out how to pack 16 channels of audio into the video and use just one router,” he says. “In the trucks, they’re constantly dealing with random audio clips that are not attached to video and need more flexibility.”

Smaller routers go more places. “We’re seeing more and more production coming aboard the truck environment, and that’s driving a closer connection between the router and the console,” says Chuck Meyer, senior VP for Miranda’s master-control business unit, which handles NVISION routers since Miranda acquired that brand last December. “The are already pretty busy on the trucks, so more flexible and more capable routers that can interface with the consoles offers more ability to fix things in real time.”

Cost trends are less obvious. Meyer says that, as routers move further into the IT realm, they become increasingly subject to Moore’s Law. However, he adds, while cost per channel decreases, the number of I/Os continues to climb: “It winds up kind of a wash in the end.”

MADI support has been a strong trend in recent years, as users seek to simplify signal transport among hundreds of I/Os. Riggs expects MADI to be used increasingly as the interface between router and console. “It’s a trend that really isn’t here just yet, and some people will say that it’s too complex on the database side,” he says. “But there is a move towards finding better ways to intelligently handle more channels, and MADI is one of them.”