Live HD Drama Makes Debut On Sky With UPM-1
UK-based satellite broadcaster Sky made broadcasting history over the summer, transmitting completely live for the first time ever a series of weekly television plays in high definition, with a 5.1 surround soundtrack. Helping to create the 5.1 ambience during transmission of the Sky Arts channel series from Sky Studio 6 in Isleworth, London, was one of the broadcaster's eight recently acquired SoundField UPM-1 stereo-to-5.1 upmix processors. Specifically, the UPM-1 was used to process stereo spot effects, atmospheres, and pre-recorded music from the Sky audio libraries so that this content was also transmitted in full 5.1.
Originally designed to allow HD broadcasters to create 5.1 audio in real time from stereo-only archive material, the UPM-1 has been used extensively on live broadcasts since its arrival at Sky's HQ in the early summer. Even during live HD sports coverage produced mainly in 5.1 surround, the UPM-1 is being used to upmix the audio from match roundups and highlights packages, which are often only supplied to Sky in stereo. However, the series of live plays, transmitted as Sky Arts Theatre Live!, marked the first occasion on which the UPM-1 has been used on a drama production.
Although weekly live drama was a staple of ITV in the 1950s and 60s with their Armchair Theatre series, it has been many years since broadcasters have attempted the 'theatre play live to camera' concept, preferring the security of pre-recorded drama and the opportunity it affords for re-takes in the event of technical or other problems. As a result, Sky could comfortably claim a first for attempting live drama in full high definition for the first time, as part of their efforts to originate more content in HD and 5.1 outside their well-established HD sports coverage. The brainchild of Sky Arts Theatre Creative Director Sandi Toksvig, Arts Theatre Live showcased completely new work by six previously unpublished playwrights over the course of its six-week summer run, and was transmitted completely live, 'warts and all', just like Armchair Theatre in its heyday.
The Sound Supervisor for the entire series was Sky's Carlton Waghorn, who explained some of the thinking behind the use of the UPM-1. "This was a very exciting project, blending some of the old skills from the heyday of live black and white transmission with the latest in 5.1 surround and high-definition broadcast technology. We had to hire Fisher live mic booms and operators, and planning the audio took a bit of thought.
"It was a question of trying to make the most of the 5.1 experience for our viewers. Once I knew that the plan was to do it in HD with 5.1, we went to the production guys and asked them to produce some HD opening titles with 5.1 theme music, and then I wanted to add as much as I could. We used a surround mic on set to pick up the ambience of the studio and the live audience, and we panned some of the output from the Fisher boom mics into the rear channels, and a little of the performance mics into the Centre channel. But I was concerned that the viewers would get the opening titles in 5.1, a round of applause in surround at the start, and then an essentially 'flat' stereo performance until the applause at the end, with the exception of the commercial breaks. What audiences really notice is when you've had all five full-range speakers active, and then all the audio disappears from the Centre channel - that really smacks you in the face. So we wanted to avoid that."
The approach was to put all of the library-sourced atmospheres and most of the spot effects and occasional stock music, which were from stereo libraries, through the recently installed SoundField UPM-1. "Our Operations Manager Keith Lane had told me that there was a UPM-1 in studio 6, and that it was there for us to experiment with off-air," explains Carlton Waghorn. "I said, 'I'm going to do more than experiment with it!' It's a great piece of kit; it brought the whole thing to life, and meant we had some 5.1 content all the way through the performance.
"For example, for the finale of one of the plays, we had some library music in stereo, which in the play was supposed to be coming from backstage. On the initial run-throughs and rehearsals, we put it through a stereo effect and just panned it left and right - we played it safe. But for transmission, we put it through the UPM-1, and it really opened up in surround. It sounded terrific. I know some people regarded it as a post-production tool when it was announced, but it is adaptive and designed to be used in real time, and we were making the most of that.
To be honest, I will be running an awful lots of things through it over the next few years, because all of our cart, music and effects libraries are still in stereo as far as I know, and if you want to make those work in 5.1 broadcast, the UPM-1 provides a really good way to do it. I imagine there won't be large numbers of 5.1 effects libraries for some time yet, and also you need to be able to deal with stereo material the clients bring you - the finale music I mentioned earlier was supplied by the client, and you can't really say, 'no, sorry, this is no good, I need it in surround if I'm going to use it'. Obviously, you can pan stuff like that left and right, but then you're not really making the most of the audio for the HD viewers."
"The other thing that's great about the UPM-1 is that it produces very phase-coherent, stereo-compatible results," adds Keith Lane, Sky's Operations Manager. "We need backwards compatibility. It's no use doing 5.1 mixes if they sound terrible when they're folded down to stereo. If we were ever going to use any kind of upmixer, we've known for a long time that it would have to be one that produces good stereo-compatible results, so that the HD viewers don't get their 5.1 at the expense of people still listening in stereo, or even mono. We did lots of testing... taking a stereo mix, upmixing it with the UPM-1 and then downmixing that back to stereo to see what the artefacts were. And the results were very good. We're pleased to have been behind another HD broadcast first, even if the live shows were a bit hair-raising at times! We look forward to doing more live HD drama in the future, and when we do, the UPM-1 will be an important part of that."