Tech Focus: Intercoms

By: Dan Daley, Audio Editor, Sports Video Group

Finding Alternative Channels

A year ago, the imminent loss of RF spectrum was the main issue confronting intercom manufacturers and users. A year on, spectrum reallocation remains a concern in wireless communications, but the growing availability of VoIP-based signal transport for communications has taken some of the edge off the issue.

“It makes sense to continue pursuing [the IP] approach for audio, and it’s gaining traction,” says Robert Pennington, sales manager for Riedel Communications’ East Coast broadcast market. “It’s easier to use for signal transport on a number of different levels, such as being able to port intercoms over to digital radios. We’ve also introduced apps that allow intercoms to be ported over iPhones and build virtual panels for tablets and laptops. Going with IP really opens up a lot of doors.”

He says that the bring-your-own-device phenomenon, which has deeply penetrated many tech fields, is beginning to do the same with intercom audio and, in the process, is driving the category toward more use of networked audio. However, the introduction of so many consumer devices into the intercom signal chain has underscored the need for — and current lack of — widely implemented standards for their integration. Several manufacturers, for instance, are looking at making their systems compliant with the AES67 protocol.

Commercial networking solutions are also making inroads. Both Studio Technologies and RTS, for example, have signed on with Audinate’s Dante networking system.

Studio Technologies’ Model 45DR Dante-to-two-channel partyline intercom interface is designed for applications that use two-channel analog partyline intercom circuits, and its Model 45DC is designed for applications using one or two single-channel analog partyline intercom circuits. Both interface partyline circuits into standard Ethernet networks.

The ADAM intercom system from RTS, which along with sister company Telex is considered the market-share leader in intercoms for U.S. remote trucks, can be interfaced with an audio network via its RVON-I/O, providing a single RJ45 Ethernet connection for use with a 10Base-T or 100Base-TX network to achieve eight-channel I/O and offering configurable network and bandwidth parameters that can be tailored to individual network functions.

In fact, the proliferation of networking protocols offers opportunities for both diversity and confusion. According to Pennington, compatibility with both AES67 and Ravenna will arrive for Riedel’s products later this year, but the company will continue to support its own networking system, RockNet, which was deployed during last year’s World Cup broadcasts. “The real goal is to remain as standards-agnostic as possible,” he says.

Not All There Yet
Not everyone is enamored of IP-based networking as the main conduit for intercom audio. Vinnie Macri, product marketing manager, Clear-Com, says networked audio is fine for long hauls and, in particular, is suited for the accelerating trend of mixing and even directing sports shows from distant central locations, an approach increasingly implemented by both ESPN and Turner Sports from their respective operational centers in Bristol, CT, and Atlanta. But, says Macri, for getting from the track, the field, the stadium, or the rink to the truck, fiber cabling is more than sufficient, offering reliability that a LAN might not under mission-critical circumstances.

“If I’m doing a press conference in the Hilton, do I need to put all the microphones and the audio console on a network?” he asks. “What do I gain in that short a space, and what are the risks I incur on an IP system? If I want to send it to Chicago, then a network is a great idea. But, if it’s only going 50 yards, I’d stick with cable.”

Macri believes that IP-based distribution solutions will coexist with IP-based ones. Clear-Com recently introduced several products intended to be used on LANs, such as its LQ-Series compact interface boxes that can connect two-wire and four-wire audio and call signaling over IP networks. But, he adds, although IP transport can manage audio easily using developing standards like AES67, control data will be harder to make fully compatible across multiple manufacturers’ platforms.

George Hoover, CTO at truck builder NEP, sees IP intercom-signal transport in remote applications coming but not necessarily quickly or comprehensively, with wired MADI remaining a reliable mode for some time: as with consoles and microphones, there’s little to compel change on the part of the broadcasters that order the trucks and specify their main platforms, and largely freelance-based staffs will still look for familiar products on high-pressure projects. What Hoover does expect to prompt the shift to IP distribution in the long run is how open standards for networked audio make different brands and models of intercoms more easily interoperable, letting projects mix and match trucks. “Once an RTS can talk to a Riedel,” he says, “it makes it a lot easier.”

The move to BYOD, networked audio, and app-based intercoms will also bring more-sophisticated communications capabilities to the growing base of midsize and small remote vehicles increasingly used as infrastructure for regional sports networks, a market that all manufacturers are eyeing.

“There’s a much broader base of sports-broadcasting users now,” says Riedel’s Pennington. “Apps and iPads are going to let us reach price points that may have kept some people out of the market before.”

What’s on the Market

By pro-audio standards, intercoms are a small market sector, but it’s a critical one. Here’s a look at the latest offerings from the market leaders.

The new FreeSpeak II operates in multiple license-free Digital Enhanced Cordless Telecommunications (DECT) bands from 1.897 to 1.933 GHz, enabling continuous, clear communication even in RF-hostile settings and eliminates the need for frequency coordination. Its active antennas and wireless beltpacks use separate data and audio channels in DECT6 to create a dependable link between beltpacks and the base station or Eclipse HX matrices. The beltpack features cellular auto-roaming technology, allowing them to constantly scan and automatically select the optimal wireless signal. It’s IP-65–rated, which means that it is water- and dust-resistant. The rugged housing is constructed of polycarbonate plastic and thermoplastic elastomer overmold, making it highly durable. FreeSpeak II is scalable: beltpack users can be easily added as the team and workload grow; the system can support 20 full-duplex wireless beltpacks. Implemented as an integrated wireless solution within Eclipse HX matrices, known as FreeSpeak II Integra, it can handle up to 50 full-duplex wireless beltpacks simultaneously. The system’s wireless coverage can be expanded with locally powered active antennas. Antennas can be positioned up to 3,200 ft. away or, when centrally powered from the base station, 800 ft. Five-way antenna splitters and up to 10 antennas can be installed to create a wide coverage zone for beltpack users to roam. FreeSpeak II beltpacks offer five intercom channels to enable efficient management of workflows. And such innovations as Listen Again message replay as well as battery-health, RF-status, and antenna-link monitoring add to the convenience of the system.

Riedel Communications
Artist is a digital-matrix platform for intercom applications and the distribution of analog and digital audio and TCP/IP data signals. The system comprises a fiber-based backbone providing a decentralized infrastructure for live audio and intercoms with matrix sizes up to 1,024×1,024 ports. Multiple frames can be interconnected by a dual optical-fiber ring to form a single large, full-summing, non-blocking distributed matrix.

Tango is Riedel’s first network-based communications platform supporting both the AES67 and the AVB standards. With its own dedicated app, My First Riedel, Tango becomes a cost-effective and efficient 40×80 digital intercom matrix. It features two integrated Riedel digital partylines, two AES67- and AVB-compatible ports, two Ethernet ports, one option slot, and redundant power supplies. The 1.5RU system has a shallow mounting depth and low-noise design and is fully compatible with all of Riedel’s current and legacy intercom panels, including the new RSP-2318 Smartpanel.

Performer digital partyline intercom system provides two- and four-channel master stations; rack-mount, wall-mount, and desktop speaker stations; and call-light indicators and two-channel beltpacks.

Acrobat full-duplex wireless communications solution offers 120 individually addressable wireless control panels/beltpacks and 18 wireless partylines. It uses the benefits of the DECT standard’s base layer, suiting it for use in crowded RF environments.

The BTR-80N two-channel wireless intercom system offers extremely reliable and secure full-duplex communication with up to four wireless TR-80N beltpacks and an almost unlimited number of half-duplex beltpacks. Variable transmit power is available up to 249 mW. Operating in a very tight frequency band (at 25 KHz vs. the 800 Series’ 100 KHz), the BTR-80N system can be used effectively in RF-difficult environments and is approved for license-free use in most countries. The system incorporates ClearScan technology, allowing users to select the optimal radio-frequency channel for communication at the touch of a button. Features include a choice of two independent or simultaneous audio channels, multiple antenna options and accessories, easy-to-read LCD indicating system status, expanded coverage using BTR-80N access points, simultaneous two-wire and four-wire intercom interface, XLR in/out for interfacing with general audio systems, auto-select condenser or dynamic microphone, and a choice of rechargeable or standard batteries supporting a wide temperature range and up to eight hours operation.

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