During the first half of 2024, I kept a somewhat steady publishing rhythm on this site. But then, over the summer, that ended. That’s because finishing the film ‘Purpose‘ became an all-consuming project.
Originally, my assumption had been: The job is mostly done once I’m going to Iceland for the film’s world premiere.
Surprisingly, that was very far from the truth.
When you watch a film at home or in the cinema, you don’t normally realise that in most cases, there are more than one version of a film — even when you stay within a single language. That’s because every film can be shown in at least two acoustic versions, as it were. One is the regular ‘stereo’ mix. We all know what stereo means — it’s for two speakers (or two earpieces on a set of headphones). One delivers the right, the other the left channel. It’s intuitive and easy to understand: We have two ears, so we listen to the world by combining two signals, from our left ear and our right ear. I have been a hobby musician for most of my life, and even though I am very far away from being a pro, my music recording experiments made me familiar with mixing stereo. You place your signals between left and right where you want them. There is more to it, of course, but in principle that’s the job.
That’s what my friend Martijn and I did when we prepared the film for Reykjavik. Because in the hall in Reykjavik, the film would be projected from a regular computer with a stereo output, connected to a large stereo sound system — not so different from using a beamer and a stereo at home. So the stereo mix was all we needed and thought about, for the time being. This type of film file is not all that different from a video that you upload to YouTube. It can be an mp4 or a mov file, with the stereo sound track built in.
However, at the premiere, the sound didn’t quite come out as I had hoped: Some of the music didn’t sound as punchy as I had expected, some of the voices had very sharp ‘S’ sounds (which can be very grating for an audience), and, even worse, there was a lot of low rumbling: Very deep frequencies that seemed to come out of nowhere, and that really disturb the overall experience. The mixing equipment Martijn and I had been working with did not properly produce those low frequencies, and he also does not have an actual sound studio. His work focusses mostly on his own short films for film festivals, and the sound recording quality during his shoots is usually better than ours had been (this had been my own and Nick Scholey’s first feature length documentary shoot, after all). So, while his set-up works well for him, the results with our film were a little less than satisfying.
The good thing is that most audiences don’t usually notice these smaller problems … so the premiere was still a success. But I knew that more work was waiting for me after my return.
Martijn was so kind to offer a rework of the sound mix, but I chose to work with a team in Berlin instead to correct these issues. One reason was that I wanted to do it closer to home, but also because I had to get the other audio mix made as well — a type of mix that Martijn couldn’t do: the 5.1 mix. The name kind of gives away what it is: Rather than two channels (like in a stereo mix), a 5.1 mix has five full channels, and an additional sixth channel for low frequencies which are played back on a subwoofer.
The 5.1 sound standard was established in the 1990s, and it is now built into virtually every cinema around the world. Two speakers are sitting in the front left and right, like a regular stereo set-up. Another speaker sits in the front at the center. Most voices (particularly in documentaries) are sent through that middle speaker. Two more sets of speakers are on the side walls of the cinema, to enable movement of sound from the side/back to the front, and to better project music and sound effects. And finally, a subwoofer is tucked away somewhere to deliver really low frequencies. (It makes little difference where a subwoofer sits because it is hard to tell for the human ear where very low frequencies come from. They kind of seem to be everywhere.)
It takes a special set-up and a skilled audio engineer to mix to a 5.1 standard. I had edited the film on Adobe’s Premiere Pro editing software, so I now needed to get the film sounds over to Kai Hoffmann at Wave Line who was going to do the mix for us. The audio software he works with is ProTools. At Wave Line, they recommended the AAF export format standard which is designed specifically for this type of situation. It would allow me to create a file that Kai could then load into ProTools, so he could work with the mix that Martijn and I had made in Premiere.
This was where new problems began. It turned out that Premiere Pro is not very good at creating AAF files. It got a lot of things wrong in the AAF export, and so Kai and I had to re-create a lot of the mix, rather than only improve on it. This made the project — which was only meant as a correction of mistakes that had been made, and an adaptation to the 5.1 standard — a much more labour-intensive endeavour. And then, we were unlucky again: When Kai exported the mix we had made, his system seemed to create a flawed file. Afterwards, it was impossible to figure out why this had happened, but somehow the mix had a lot of distortions in it. When my producer Jan-Peter and I listened to the results of Kai’s and my mixing work, we were very confused. We did not imagine that the file was the result of computer errors. But we also couldn’t imagine that this was really the result of what Kai and I had worked to create. Long story short, we had to go back and review everything again with Kai.
I then had the chance to watch and listen to the 5.1 version of the film in a small cinema in Berlin, the Sputnik. Unfortunately, there I noticed that some levels of the voices still weren’t quite right — my voice was very loud while the voices of the other protagonists were comparatively low. Re-adjusting all of these balances across the entire film again took some time. It also forced me to stay in Berlin and not attend the idfa Docs for Sale market where we had been included with the film. Gladly, my colleague Juan had the chance to go and represent ‘Purpose’ there.
Meanwhile, we were also working on the German version of the film. There were two parts to this job. One, I had to re-create my English voice-over in German. This went surprisingly fast and was easier than I thought. But then I also had to create German subtitles for the entire rest of the film. That was one of the hardest jobs I had to do for the film. I only realised in the process that creating subtitles for a film is not about translating it. The translation is only the first step, the easiest part. What’s a lot more important: You then need to recreate the words of the film in a way that corresponds with people’s on-screen reading habits and with their capacity to listen to one language and read the other. Simply put: If you have never done this before, the potential to fine-tune and improve subtitles is pretty much endless. Several times, I thought ‘Oh I’ll do a quick one-hour subtitle review session this afternoon’, and then I sat there for six hours working on it deep into the night. There were days when I thought I’d never get it done.
Also, the German voice-over needed to be brought into the audio mix that Kai had created. So this was another step in the process.
Now, in order to create a film that can play in cinemas, the 5.1 mix may be the biggest job. But it’s not the only one. You also need to make a specific set of files that are especially designed for cinemas, the so-called DCP — which stands for ‘Digital Cinema Package’. The 5.1 mix is part of that. Wave Line also did that job for us.
And that’s not all. While all of this was going on, my colleague Juan and I were busy at work trying to co-ordinate all the marketing and promotion efforts for getting screenings going, getting the film out to places that were putting on screenings (stereo files first, the DCP 5.1 versions later). And I had the job to produce and organise the big German premiere which we had on November 25th in Berlin, and which included a lot of partners and moving parts.
After the Iceland premiere, we managed to put on the first 20 screenings of the film in 2024, in six countries (UK, Australia, Germany, France, Switzerland, New Zealand), and almost 1,200 people saw the film that way. (For a full 2024 wrap-up of ‘Purpose’, click here.) And we are now continuing to organise screenings throughout 2025 — if you want to show the film yourself, let us know on this page!
To sum it up: All of this is why I sort of stopped publishing on this website since the summer (except the film’s trailer and our new Instagram profile). There simply wasn’t the time.