For Chris Stangroom, VP, sr. sound designer/engineer of New York-based HOBO and the supervising sound editor on the new Netflix documentary feature Amanda Knox, his work on the new film features what he calls “musical” sound design. “The sound design plays off of pitches and timbre to help build on emotions the filmmakers want the viewers to feel in each scene,” Stangroom said.

Stangroom discusses his work on the film–directed by Rod Blackhurst and Brian McGinn–the challenges it presented to him and the HOBO team, and his ongoing collaboration with audio engineer Tom Paul of Gigantic Post, NY.

Q. This project comes on the heels of your collaboration with Tom Paul and Gigantic Post on another high profile indie doc, Weiner. How does your work on that film compare with Amanda Knox? 

Stangroom: I had my hands in this film much more than Weiner. For that film I was the dialogue editor, but for Amanda Knox I joined the film as the supervising sound editor. I was more involved with the entire post audio process: Putting the sound editorial team together, communicating with the film’s producers/directors Brian McGinn and Rod Blackhurst about their sonic vision for the film, as well as connecting with the music composers (Danny Bensi and Saunder Jurriaans) so we always had the latest music cues and sound design to work off of.  

Overall, the sound was evenly split between creating the realism of the film as honestly as possible, and more cinematic sound design that we used to represent the emotion and journey of this unbelievable case. The sounds we decided to use for the small town of Perugia, Italy were very specific. In those ambiences you’ll hear lone car engines, the occasional barking dog and a Vespa scooter or two.  We contrast how eerily quiet Perugia usually is compared with the media frenzy of the Knox case.  As the drama unfolds we used a more cinematic sound design approach to help amplify the tension that was constantly growing with the film.  

HOBO sound effects editor Diego Jimenez has a skill like no one else in finding tense sounds and twisting them to grow and build into a soundscape that leave you feeling uncomfortable.  Bringing those elements in at key moments help create the overall audio texture for the film.

Q. Where there any particular scenes that you found most challenging or creatively interesting?

Stangroom: I find the opening scene so spooky. Rod and Brian made a great decision to start this film about such a controversial case with the actual police footage from when they responded to the call about Meredith Kercher’s death. Every piece of that police footage that you see in the film is untouched. We supplemented those raw sounds with natural ambience of Perugia, as well as subtle Foley touches.

My favorite is the final scene inside the church where we hear these eerie reverbed whispers and a low sub-harmonic drone that builds the tension. That scene cuts to a ferry in Seattle with Amanda Knox aboard looking weary from the media attention. We tried capturing that feeling sonically with layers of low vibrations, a pitched down sound of churning water and distant drones swaying in and out of the music.

Q. HOBO and Gigantic Post have collaborated a lot recently on several notable indie documentaries. What’s the creative partnership between the two companies like? 

Stangroom: HOBO and Gigantic have been collaborating for about five years. I’ve known Tom Paul for more than a decade, and he is one of the top documentary film mixers out there. He pushes us all to look deeper and find the smallest details of any scene. It’s his attention to small touches that make him who he is. He’s trusts us with the full sound editorial on a lot of his projects, adding and tweaking the overall soundscape to build on what the directors and producers want the film to sound like. 

Q. What technology did you rely on for this?

Stangroom: For this film we relied heavily on ProTools 12.  We use Soundminer for all of our sound effects libraries. I also use Native Instruments’ Reaktor a lot these days to find variations of realistic synth sounds to layer with the ambiences and music in the films I work on. Omnisphere is another great tool that helps us set the mood and tone, especially in a film that wants to help build a sense of unease or dread. Izotope RX is required for every documentary out there these days. 

Q. You’ve worked on a number of indie film projects in the past. Where does this film sit for you as a creative accomplishment?

Stangroom: Amanda Knox is probably the most unique documentary soundtrack I’ve ever worked on. There were a lot of cinematic references made by the directors and editor Matt Hamachek.  We worked hard to craft a film that could make an emotional impact even if you muted the interviews and dialogue in the film. It’s success is a testament to many talented people in this process, especially Rod, Brian and Matt who gave us detailed feedback and helped direct us all to an incredible final mix. 

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