CTV Offers Reflections on Olympics Audio

Michael Nunan, post sound supervisor for Canadian TV network CTV, and Joshua Tidsbury, CTV systems specialist and post sound mixer, kicked off the broadcast sessions at the AES Convention last week with an overview of their massive efforts related to the 2010 Vancouver Olympics.

Collectively, more than 2,450 hours of content were delivered over 17 days on 12 TV networks, and more than 2,200 hours were delivered over the Web. Also, more than 20 languages were supported, a complex audio challenge that would be difficult in stereo. But CTV, in an effort to wow viewers, decided to deliver everything in 5.1 surround sound.

Tiny Puzzle Pieces
“One of the very tiny pieces of the puzzle was the production of the Olympics Suite, a music package for the games with more than 240 cues that was delivered as more than 1,100 pieces of audio media,” said Nunan. “And during the games, we wanted to act as a straight wire, delivering 5.1 surround audio from the venues without getting in the way.”

All production elements were also produced in 5.1, requiring all production systems to pass 5.1. In fact, systems were capable of passing not only 5.1 signals but both an English- and French-language commentary track as well.

“We also needed standards-based downmixing, as a massive number of viewers and consortium members were in SD,” added Tidsbury. “So an audio mixer needed to be confident that they would know what that mix would sound like.”

A Single Tech Spec
One of the initial challenges was a unified technical specification to ensure that content could easily be passed from one network to another. Among the questions asked of broadcasters that would transmit the coverage were whether they were an HD or SD network, needed 5.1 surround sound or stereo, passed Dolby E-encoded surround or discrete 5.1 surround, needed metadata, and wanted an English or French commentary.

“The trick to it all was to eliminate the gear changes when going from one format or workflow to another,” said Nunan. “We had to be format-agnostic. So, by building everything in 5.1 surround sound, we avoided the handcuffs and minimized the number of times the operator needed to think.”

While it wasn’t practical to have everything (such as a mono microphone) in 5.1, everything needed to at least appear 5.1 “legal.”

Starting From Scratch
Pre-production before the event also laid the groundwork for the 5.1 surround experience. And it often meant working from scratch.

For example, pre-production video elements of skaters, skiers, curlers, and other athletes needed 5.1 audio tracks for effects related to the sports. But audio-effects libraries don’t have 5.1 surround elements for such sounds as a skater completing a triple axle or a ski jumper blasting off the ramp. According to Tidsbury, audio elements were built by attaching lavalier mics to the side of skis or a Holophone mic to a bobsled in order to capture the true sound of the sport.

“Prior to the games, we had the luxury of being able to ask the skaters to get as close as they could to the microphones to achieve the sound we wanted,” said Nunan. “We needed to have the building blocks for a discrete surround-sound experience, and the aggregate effect was something quite wonderful.”

More than 1,000 billboard packages were created prior to the games, and all elements had to work properly with different platforms, such as Harris Velocity editing systems, Inscriber character generators, EVS replay servers, and Avid editing systems.

A 576×576 Evertz EQX router with a TDM matrix was at the heart of the surround-sound productions. Lawo MC56 Squared audio consoles communicated to audio systems via seven MADI lines, two hooked up to the outboard input/output panel and the remainder to the router.

Every program source had 16 channels of audio, and, in mixing, the first fader opened six channels in 5.1 surround sound with the voiceover in channel 3.

How To Listen to 5.1
“The trick was also to train everyone how to listen to 5.1 surround sound,” added Nunan. “What do you expect from the sound field? How do you trust your instinct relative to how the sound pressure hits you? Everyone needed to learn to mix to make the music relative to the commentary.”

Tidsbury said the recording of the Olympics theme music was also a major undertaking, with eight musical themes used to build 240 individual pieces of music.

“We needed a lot of audio cues so we wouldn’t beat one or two to death during the Games,” he added. The Montreal Symphony Orchestra was recorded at McGill University, and a children’s choir was recorded in a Masonic Temple in Toronto.

During recording, multiple surround microphone arrays were placed around the room to capture the essence of the recording. Tidsbury said the process was like building a Lego set so that the Olympic production teams could build anything they wanted.

“Just like with the sports elements, it was all built with 5.1 delivery in mind,” he said. “And, by capturing source material in 5.1, the quality of the signals can survive any process you throw at it.”