In Quentin Tarantino’s latest film, Once Upon a Time in Hollywood, re-recording mixer Michael Minkler and veteran music editor Jim Schultz were tasked with delivering an unrivalled audio production. As the film relied on well-known original radio broadcasts, songs and scores from the 1960s era in which it was set, the duo selected NUGEN Audio’s Halo Upmix plug-in to allow them to mix from stereo to 5.1/7.1/Dolby Atmos and back again.

“Quentin values the authenticity of his material, from the master recording through to the reproduction and re-recording, and how it’s used in the film,” said Schultz. “One of the most important things I think we do with Quentin is to stay true to the original source as close as we can and work it into the film in a way that serves the narrative and serves the authenticity of the recording.”

For Tarantino, the immersive nature of the film’s audio starts with the dialogue. “Everything has to be real on the set; he never loops any production dialogue,” said Minkler. “Whether it’s music or dialogue, we must always work from the original source, that’s the one that’s gold and you can’t change it. For this film, he had to lighten up on that quite a bit because there was so much music involved – at last count, we used 107 drops of music. Jim spent a tremendous amount of time using the original source, but then Quentin gave us the flexibility to experiment with newer vinyl, digital and broadcast recordings, with the caveat that it had to be the exact pitch and time as his original to ensure there was no disjointed audio. So, Jim spent a huge amount of time doing that.”

Halo proved extremely helpful in creating an exact pitch to the originals. “Some of these sources were mono or two-track stereo; nothing was five-channel or higher,” added Minkler. “We’re living in a 7.1 world now, so Once Upon a Time in Hollywood had to fill up the room, but only to the level that fits and sustains the flow of the film. Sometimes we stayed within three or five channels and other times we’d go up to seven channels or Atmos. In some cases, however we had to upmix to 7.1 from a mono source, which is a little trickier but with NUGEN’s Halo Upmix, we were able to do it successfully.”

Schultz says that his strongest takeaway from working with the NUGEN software is the flexibility that is coded into it. “Halo really gives the end-user the flexibility to dial-in the type of upmix they want,” he concluded. “That includes everything from center channel diffusion, to low-frequency loading and dispersion out of the center channel to width of the surround as well as the diffusion into the surround. For creative upmixing, there’s not a one-button set-it and forget-it process. We really need the tools to be able to dial it to our taste and intent, especially on a film like this. Halo Upmix was a welcomed addition to our workflow on Once Upon a Time in Hollywood, and we made good use of it, too – nearly every featured song in the film went through the software.”