ST350 Proves Invaluable To 'Harry Potter' Sound Team
Production on Harry Potter And The Half-Blood Prince, the sixth film in the series of adaptations from JK Rowling's successful novels, is already well advanced, with the film scheduled for a November 2008 release. Attention tends to focus on the amazing visual effects created for the Potter films, but this time around some pretty impressive sonic wizardry has been employed at the post-production stage, almost worthy of Harry himself, courtesy of a SoundField ST350 Portable Microphone System (pictured left in Pelicase with Rycote and Battery Kit).
John Casali, Second Unit Sound Mixer on the film, has been a SoundField fan for some years, and rented an ST250 for the last big Hollywood production he worked on. Encouraged by using it there, he decided to acquire the updated ST350 in time to use it on the latest Harry Potter film.
SoundField's mics are renowned for being able to record in their own proprietary four-channel format, known as SoundField B-Format. When decoded by a suitable SoundField hardware or software processor, the B-Format signals can be rendered as audiophile-quality, phase-coherent stereo, M&S, 5.1 or any other multi-channel surround format, simultaneously if required, despite the recordings only having been made with a single microphone. If the four-channel B-Format signal is recorded to a multi-channel medium, the decision about final output format can even be determined later, at the post-production stage. SoundField's software and hardware processors also offer a great deal of control over B-Format signals, allowing sound recordings made with a SoundField to be 'rotated', 'tilted' or 'zoomed' in post-production, creating exactly the audible effect that would be achieved by physically moving the mic closer to its subject or changing its orientation, but without having to touch the mic itself.
Not surprisingly, all of these possibilities for creative post-production greatly appealed to a sound engineer working on a complex sound stage like that of Harry Potter. John Casali had used his rented ST250 chiefly as a high-quality stereo mic on his previous project, but on the latest Potter he decided to begin recording in four-channel SoundField B-Format, reasoning that if his experiments didn't work out, he could always render the signal in simple stereo anyway. "I think SoundField's mics make lovely stereo recordings," he explains from the film's sound stage, "but on a film like Harry Potter, the audio post-production guys quite often like to have an Mid & Side signal anyway, as it allows them more scope for altering the perceived stereo width at the post-production stage anyway, and it can be useful as the basis for surround sound mixes. With the ST350, I could give them stereo or M&S from the one mic."
Casali rapidly progressed to giving the audio mixing team the raw four-channel B-Format signal, so that they could choose the end audio format of the signal themselves. "My colleague doing work-in-progress audio mixes is called Jamie McPhee, and when I first explained what the ST350 was capable of, he was a bit sceptical, and said 'look, just give me M&S or stereo'. But when I showed him what you could do with the B-Format signals and gave him a copy of SoundField's Surround Zone software decoder for Pro Tools, something clicked. I've mostly been giving him B-Format signals since then, and leaving the format and mixing up to him. The ST350 has been invaluable on the crowd scenes in the Great Hall at Hogwarts, for example, where instead of hanging multiple mics to catch all of the ambience, and having a complex job of mixing it later, we can just use the SoundField and focus on the parts we want in the post-production. As Jamie said to me the other day, 'the more you use this mic, the more uses you find for it!'"
