Recording clean dialogue beside a waterfall

A major scene on Lord of the Flies, played out metres from falling water. There is no plug-in for that, and there was no single trick either. There was a series of decisions, made in order, and one of them made post-production's day.

On Lord of the Flies, the BBC and Netflix adaptation of 2026 and the most recent of several over the last sixty years, we had a major scene play out metres from a waterfall.

One thing is for sure: there is no plug-in for your mixer that deals with that. And there was no single trick either. What there was, was a series of decisions made in a particular order, and underneath all of them one idea. Do not fight the environment. Work with it. Record it.

Most producers I have worked with will, understandably, say at some point that we will fix certain things in post. For most problems that is a perfectly valid answer, because post-production is extraordinary now.

But battling dialogue against a torrential waterfall is one of the specific cases where it just ain't true, and it is worth understanding why, because the reason informs everything you do on the day.

Why a waterfall cannot be fixed later

Most noise you can remove has a shape. A generator hums at a frequency. Air conditioning sits in a band. A fridge cycles. Modern noise reduction is extremely good at finding something with a shape and subtracting it while leaving the voice intact.

Falling water has no shape. Neither do cicadas, which is why a New Zealand summer bush location can be just as unforgiving as a Malaysian waterfall. Both are broadband and effectively random, and both sit directly on top of the frequency range where speech intelligibility lives. The noise is not next to the dialogue. It is inside it. Try to subtract it and you take the consonants and the sibilants with it, and the actor ends up sounding like they are talking through a wet pillow.

There is always ADR, and it genuinely has its place. Sometimes it saves a word or two. Sometimes it adds something to the story that was not apparent to the director on the day. But ADR costs money, costs schedule, and almost never carries quite the same performance. Post can only optimise what the actor actually gave you on the day.

So when there is a chance a line can be salvaged in the field, we run with it, every time. There is some sort of duty at work there, which any experienced mixer will feel. And never at the expense of the director's vision or of the performance, because if you damage either of those then the whole thing was for nothing anyway.

Decision one: the boom, as tight as the frame allows

Proximity is genuinely number one. The inverse square law is the only improvement available for free on a location.

Halving the distance between the capsule and the actor's mouth gains you roughly six decibels on the voice, while the waterfall, effectively an infinitely large source spread across the whole environment, remains exactly as it was. That is a very big win for very little.

The other half of it is aim. Point the microphone away from the falls, not across them. Obvious when it is written down, and yet the pressure of a moving set makes it the first thing to slip by.

On coverage the boom operator commits to an angle and holds it. Always from underneath, or always from above, or always from the same side. Consistency of angle matters as much as consistency of distance. What quietly ruins water scenes is not the noise level, it is the noise changing. If the wide has the falls at one level and the close-up has them at another, every cut in the sequence draws attention to itself.

On the wide shot, forget all of the above. There is no place for the boom.

Which means the whole thing is a conversation with the camera department and with the director rather than a problem to be solved with equipment. It can only be solved with understanding. How tight is the frame. Could a slightly longer lens buy fifty centimetres of boom room. Is there a shot order that gets us in close on the coverage even if the wide is a write-off.

It is worth being clear about how that conversation actually goes. It is not my job to tell a director how to shoot a scene. They bring the vision, and to be frank the narrative, the performance and the visuals all matter more than my track does.

But directors usually have several ways a scene could go, not one, and if I stay quiet the second option never enters the conversation. So you speak up, quickly, between setups, and you offer rather than demand. A great deal of good can be done for sound that does no harm whatsoever to the visuals or the narrative. That is how every senior mixer I admire works. Collaborative, fast, and with real tolerance for everything else that has just as much right to be in the film as sound does, if not more.

On this scene Adyt Santoso was on boom, and honestly a great deal of what made it work was simply him being braver about the frame line than a less experienced operator would have been. It is the ballsy call, and he made it every time. Adyt is fearless in a way that changes what is possible. That is not a technical decision. It is trust, built over many months on this show and many years of working together before it.

Decision two: radio mics, rigged and re-rigged

Concealing radio microphones on a young cast in a rainforest, working around chaperones, across multiple locations out in the bush, is its own discipline.

On Lord of the Flies the costumes degrade across the series, aggressively and quite intentionally, which is exactly right for the story and exactly what makes concealment hard. Each week there was less fabric to work with, and more heat, sweat and movement to contend with. Occasionally the boys were found wearing salvaged clothing, which quietly gave us somewhere to hide a capsule again.

Toto and Muel Yow in costume were extraordinarily helpful and extraordinarily competent throughout, which on a show like this is not a courtesy but the reason the rigs worked at all.

DPA capsules did their job, rigged and re-rigged at every costume change. There is no clever answer here. Only attention. You reposition, you re-tape, you re-check, and you accept that a rig which worked yesterday may not work today.

Sound utilities on that unit was Reza Feryanto. Reza never gives up and he always has another trick left. Every time we were caught out by clothing noise, or wind, or movement, Reza would go back in and try the next thing.

Which is the actual point, and it took me a while to see it properly. Attention on its own is not enough. It is attention plus the willingness to keep going back. Without the willingness, the attention is worth nothing at all.

Beside a waterfall the lav earns its keep differently from usual, and the comparison with the boom is genuinely interesting. It is not necessarily cleaner. Both microphones give you a different ratio of noise to voice. The body hides and insulates a surprising amount of what is arriving from behind and below, which the boom gets no help from at all. The boom, up close, gets the clearest voice. In the mix, having both perspectives is worth far more than having either one be perfect.

Decision three: the one that made post's day

This is the part I would do again on every location like this one.

We recorded the falls and the surrounding rainforest as full surround material on a Sennheiser AMBEO VR microphone, with its four capsules. Not a token thirty seconds. Hours of it. A real library: multiple positions, multiple distances, different times of day, long unbroken takes, recorded both with the unit present and with the location entirely to itself. A good deal of it was captured at weekends and before sunrise, when nothing else was moving.

That changes what post-production is being asked to do, though not quite in the way it is usually described. Nobody is removing the water from my dialogue track. That was never possible and still isn't. What changes is that the dialogue track no longer has to carry the world as well as the words. The environment lives on its own tracks, recorded on purpose, so post can ride the dialogue for intelligibility where the lines matter and let the recorded rainforest carry everything in between and underneath.

A good deal of the waterfall you hear in the finished show is the one we recorded deliberately, at the times of day we chose, placed where the story needed it. The rest was sourced separately by the post team to help isolate the elements they needed.

Post on the show was led by supervising sound editor and re-recording mixer Niv Adiri, who won both the Academy Award and the BAFTA for sound on Gravity. The material only mattered because his team knew what to do with it.

Which brings me to a phrase I would happily retire. "Fix it in post" implies correcting something badly wrong, or creating something that was never there at all, and that is a visual effects conversation more than a sound one. What post-production actually does is polish and optimise. It takes what it is given and stretches it as far as it will go, which is a very long way in the right hands and no distance at all in the wrong ones. Give it something worth stretching.

In short

There was no single fix. There was not wasting anyone's time, being on cue, miking up in the right sequence alongside costume and makeup, watching the blocking, and being in the DOP's or the director's ear when it was needed and nowhere near it when it wasn't. And there was the important one, recording the environment properly whenever the chance presented itself.

Location sound does not need more budget to fix problems. It needs conversation.

The noisy places are almost always there for a reason. Either they are unavoidable, or they look wonderful, and usually both. So embrace it, work with it, talk about it, and get the best out of it.

Ande Schurr is a production sound mixer based in Singapore, working across Southeast Asia, Australia and New Zealand. Field Notes is written from the floor. Lord of the Flies sits alongside the rest of my credits.