IP – the source connection in audio post?

As ISDN enters its last days audio over IP appears the natural successor, with specific programs on the market aimed at broadcast voice projects.
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When ISDN (Integrated Services Digital Network) was first demonstrated in the early 1990s linking studios in different countries for voice and music sessions, strong doubts were aired regarding audio quality and the problem of delay. Dedicated telecom circuits were expensive but the argument was they were tried and tested and couldn't – or shouldn't – be usurped by this high tech newcomer, even if it was cheaper to operate.

Twenty or so years later, similar arguments are being had over audio or voice over internet protocol (AoIP/VoIP) replacing ISDN. The same quality and latency points are being made but IP is rapidly becoming the technology of choice for speech-based broadcast and post-production work between facilities in different locations.

The drivers behind the shift to AoIP are perhaps even stronger than they were in the 1990s. Programme production budgets are tighter, turnaround times shorter and post houses are looking to get as much use out of their facilities as possible. IP is part of the technological infrastructure through the main IT network but companies are realising that having ADR sessions on the same circuits as general telephony and internet traffic is not ideal.

Hardware codecs offering IP along with ISDN and other established telecom protocols have appeared on the market over the past few years but software options are now seen as a viable option. Among the leaders in this is Source Elements, a US-based company that produces the Source-Connect remote recording application.

The Source-Connect software package can be bought outright or rented on a session by session basis. It supports 64-bit AAX and audio components for Mac OSX, as well as RTAS (Real Time Audio Suite) and VST (Virtual Studio Technology), among others, for all other operating systems. Now in version 3.7, Source-Connect can run on T1, cable or DSL internet circuits as an alternative to more expensive ISDN or hardware and subscription based lines.

Source Elements was founded in 2004 by John Binder and Robert Marshall, who come from a post-production background, along with director of technology Rebekah Wilson. She says the aim behind Source-Connect was to offer a replacement for existing technologies. "ISDN is being cancelled in Germany, the Netherlands and Sweden," she says. "The intention was to have Source-Connect be there when ISDN is not."

Wilson explains that the program has "four to five main uses", with voice-over work key among them: "Voice artists are using it as the primary means of connecting to studios or as a back-up for ISDN or when they're travelling."

Wilson says the cost of buying the software is the same as renting an ISDN line for day and that the internet is now providing a practicable platform for professional work. "What's really exciting for us is seeing how good the internet has become in the last few years," she comments. "I live part of the time in Mexico and getting connections for working hasn't been an issue at all."

Professional facilities have had less positive experiences with IP but Wilson says they need the right conditions: "If they're running only one internet connection then they're sharing with hundreds of other people. They need to install DSL or a specific T1 line to make it really work."

Source-Connect is used widely in the US, with the user base in Europe growing. ADR sessions between Hollywood studios and UK facilities is a major area, as is linking post houses in different parts of the same country. The media scene in Manchester is expanding rapidly but, despite the BBC moving several departments to MediaCityUK, the majority of on-air talent is still based in London.

Consequently post-production companies in the northwest are seeing Source-Connect as a workable form of connectivity for ADR and voice-over work. VTR North in Manchester has been using the program for sessions connected to London; dubbing mixer Nick Netsall says he is "not a fan of ISDN" and finds Source-Connect "a useful tool for ADR sessions" because of the low latency at both ends. "It's still in its infancy but it does give better sound quality over the internet and you can sync two different systems remotely," he comments.

Rebekah Wilson emphasises the practical benefits of technology like Source-Connect but ultimately has a higher ambition: "I'm from New Zealand, which is very remote, so it's my dream to get everybody working together without geographical issues."




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