Director James Wan is best known for his horror films — like Saw, The Conjuring films, and the Insidious films. He knows how to build suspense and how to make room for big sound moments — two important skills he put to use on Warner Bros. Pictures/DC Comics Aquaman. Tidal waves, underwater battles, an evil race of ocean-dwelling creatures known as the Trench, and a spinning vortex of sonic turmoil are just a few of the massive sound elements that Formosa Group supervising sound editors Peter Brown and Joe Dzuban tackled for Aquaman. Dzuban was also the effects re-recording mixer, working alongside re-recording mixer Tim LeBlanc on dialogue/music on Warner Bros. Stage 10.

Another challenge they faced was working with water. That inherently white-noisy sound eats up sonic space and can easily make a mix muddy. Through effects processing and smart mix decisions, the team was able to keep the water sounds contained and craft a soundtrack that has both dynamics and clarity.

Read on to find out how Brown and Dzuban, along with sound designers Eliot Connors and Stephen Robinson, created everything from Trident hits and ‘laser’ guns to underwater vocals for Aquaman.

What were director James Wan’s initial goals for sound? How did he want to use sound to help tell this story?

Peter Brown (PB): The first thing out of everybody’s mouth was how do we get these guys to talk underwater? That was the million-dollar question. They had the concept and knew they were going to do it but they didn’t know what it was going to sound like and what it would take to sell that idea. So that was the first types of design we started to roll through and send over to the picture department.

Whenever you do a vocal treatment, the first rule is that the dialogue needs to be intelligible. Things are fast-paced in an action film and you have one shot of hearing what’s going on. Often there is a lot of plot information transferred in those words. So you can’t do anything that is too crazy…

Joe Dzuban (JD): Or too realistic! One of our sound designers Eliot Connors has some underwater IRs (impulse responses). We listened to some tracks with actual underwater IRs and it made the dialogue sound completely submerged and unintelligible. At that point, we knew that we couldn’t take a literal approach. We had to find an approach that worked for the film that we could establish and minimize here and there. So it was smoke and mirrors. You come up with something that works for the scene and then you pare it back a bit — not to the point where the audience can perceptively hear that you backed it down but just so there is enough clarity on the lines.

What did your processing chain look like for the underwater vocals?

PB: We started off with phasers, flangers, ping-pong delays, and deep echo. We’d take the same dialogue lines and do different vocal processing on them and send them over for review. But the dialogue lines that sounded really interesting were just too interesting for the dialogue to work in the film. It was bouncing around and too echo-y.

By the end, we had pared it back to a little bit of flange and a bit of phase, if we needed more there was an additional reverb, ping-pong delay, and echo to put on there.

The processing wouldn’t be the same for every line. We would hit it hard the first times people would be talking underwater and then dial it back.

JD: It was completely done to taste for James [Wan]. Sometimes the character had a rise in their performance, then James would want to hit that with more water echo for dramatic emphasis.

PB: Like that line from Vulko (Willem Dafoe) in Reel 2 when he yells, “We’d honor you, King Nereus!” James wanted to hit the echo and reverb on that because it was a shouted line.

Also, as the characters moved closer or further from camera Tim LeBlanc would continually tweak the dialog processing making it sound dynamic and alive.

Water is a major component of this soundtrack. Did you do any field recordings of water, in water, or with water? Can you tell me about your water sound collection for Aquaman?

The second request was, “No bubbles.”

PB: The dialogue was the first request and I think we nailed that in temp one. The second request was, “No bubbles.” James initially didn’t want any bubble sounds in the film. He wanted this film to sound unique and be tailor-made. If you look back at water films that have been done in the past — and what springs to mind is The Abyss — it just seems like the sense of being underwater was always done with bubbles. So they gave us this command to not use bubbles and we found it really difficult to work with sounds of water that had already been recorded.

So we headed out into the field and captured a bunch of recordings. We recorded off the coast of California. Our sound effects recordist Charlie Campagna had captured some whale recordings in Hawaii. We recorded in a 50-gallon drum in a parking lot. We recorded in buckets in our voiceover studio. We took over Joe’s pool one day and recorded in there. This is on top of source that Joe and Eliot had captured while working on a big underwater sequence for Power Rangers.

JD: The scope for that film wasn’t so grand in terms of its water sound effects. We had done a day of pool recordings using air compressors and cans of air that allowed us to do slow air releases underwater to get the idea of fluid movement and bubble travel.

A really fun recording we made was in Peter’s studio using a large block of dry ice to generate bubbles. We used his Sanken CO-100K mic to capture the exterior sound (i.e., not underwater).

PB: That was a useful microphone. It allows us to record up to 100 kHz, which is far above human hearing. With those recordings, we could do some extreme pitching down of the water that we recorded.

We also captured the dry ice underwater with a couple new hydrophones. We used a pair of ASF-2 compact underwater microphones by Ambient Recording, which expanded our hydrophone universe for getting actual sound underwater.

JD: We didn’t want to have the same bubble sounds every time we were underwater. We wanted it to sound different and we wanted to play with water in as many different ways as we could.

I often went back to those dry ice recordings captured by the Sanken CO-100K because the raw material was so good. You could mangle it, tweak it, and pitch it in so many different ways. Those sounds ended up in numerous places throughout the film.

PB: We tried to capture thicker water sounds, using cornstarch in water so that it was like a viscous mud. But those sounds weren’t so useful because the bubbles were so slow.

The sounds we got from the dry ice and from the compressor — the rapid bubbles — seem to be more useful.

JD: Yeah, the source recordings were very versatile. You could take a single recording and make it into tight fluid movements, like for when Aquaman [Jason Momoa] was pushing a submarine through the water and there are all of these tight bubbles coming off of his body. Or, you could slow it down and make it into a deep underwater atmosphere, like the low, churning quintessential underwater sound you would hear in films.

PB: One of my favorites was using a water filled fire extinguisher that we could pressurize up to 100 psi. We squirted that into Joe’s pool and captured it with the hydrophone. That was helpful for underwater explosions. If you take those sounds and pitch them down, you’d get this weird, deep plunge or explosion-type sound. Shooting water into water was as good as capturing air coming up out of the water.

So in the end, it was ok to use bubbly sounds?

PB: So the punchline of that whole earlier quest to not use bubbles was that we discovered the sound of being underwater is bubbles! That’s what you hear underwater. Aside from sea creatures, such as whales or shrimp (which make a clicking sound), for the most part sound underwater is bubbles. So we just had to play with that.

Eventually they came around and the visual effects supported bubble sounds. As the visuals became more honed, you’d see Aquaman swimming fast underwater and there would be little bubbles coming off of his body.

JD: It was actually a funny thing because it went from no bubbles, to a little bit of bubbles, to muffled bubbles, to brighter bubbles. We were constantly tweaking it to get it right in the pocket.

PB: There was one pass that we sent over early on and the picture editor Kirk Morri said the bubbles sounded like they were too close to the surface. The action is taking place on the bottom of the ocean, so anything that sounded too light or airy or splashy we got rid of. We used sounds that didn’t have a whole lot of high-end or white noise. We went with sounds that were deeper and had more low-end, so that it would sound like they’re coming from deep in the ocean. We’d carve the high-end frequencies off or pitch the recordings down and that would make the sounds more appropriate for what they were going for. It was definitely a process.

For the above water sounds, how did you give those an interesting ‘voice,’ so it wasn’t just whooshy white-noise? Any tools or tips you can share for effectively working with water sounds?

PB: The tidal wave scene encapsulates the problem that you are talking about. In the scene, the Atlanteans are sending a warning to the surface in preparation for their big attack. So they send these gigantic tidal waves to knock all of the warships and garbage out of the water and onto shore. We see Aquaman as he is driving down the road. He looks up to see all these seagulls fly overhead and he hears a rumble as this destroyer is surfing in on a gigantic tidal wave.

We worked really hard to get that sound just right for the wave coming in. We were close to having something that worked but the problem is that when you have that much water, something so gigantic it could push a destroyer, that there’s inherently a lot of white noise. It was very difficult to get it feeling like it was coming closer and closer, I think the build was getting gobbled up by the white noise.

If you want something to seem very loud, you should have something very quiet preceding it.

The solution was interesting. We ended up taking all of the sound out and just playing the music. This was one of the ideas that is very typical of James Wan. He can recognize something that isn’t quite working for the scene and come up with a radical, new approach for it. So we lived with that for a few days where the whole sequence is all music until the wave actually hits Aquaman. But that wasn’t quite right either. So we decided that when the boat actually hits the ground, we’d need to be back into the effects for that moment. But we waited until that moment to have effects so that it has a maximum impact. If you want something to seem very loud, you should have something very quiet preceding it.

We dialed the effects back at that point but it still felt like there was something missing from the wave. So instead of going back to the white noise, we used a very ominous rumble. I think we went through 12 different rumbles before we got one that James was happy with. It was a nice horror-film rumble and that was a great choice because it gave the sense of this huge wave getting closer and closer but it wasn’t encumbering us with white noise, which is what was frustrating our previous attempts.

There’s a scene where Aquaman is whirling around the Trident, catching the water, and the sound is reverberating off the metal ship. How did you handle the sound for that scene?

PB: That was kind of a complicated process. It started out with Charlie Campagna’s recordings of a hose. He used a contact mic strapped to a cloth hose that was shooting water into a bucket where he had a hydrophone capturing that sound. He would unpinch the hose a little bit and you can hear the water moving through the hose via the contact mic and then hear it spraying into the bucket at the end via the hydrophone. It goes from no pressure to high pressure water moving through the hose and you get these watery whooshes.

Then Eliot took those and pitched them way up so that it sounded much faster than the original source recording. He used a complex chain of PhaseMistress and FilterFreak by Soundtoys. The result was this long recording of those water whooshes that sounded like a fast swirl or whirling sound. I think that got us through the pre-dubs.

At the very end, when the final VFX were coming in, we wanted to take it to the next level so Eliot ran that material through Tonstrum’s Traveler plug-in. It creates a spiral movement to the sound with a little bit of tremolo and of course massive compression. The end product was this really great spinning sound that had enough detail to stick out without the white noise. A touch of actual water spray topped it off matching the visuals of water spraying onto the ship’s hull.

What went into the sound work for the fight on the ship with the Trench?

PB: That’s one of my favorite scenes because of the contrasts. That scene went through a lot of different iterations. The first times we worked on it the note from Kirk and James was that these Trench creatures need to be screechy, sharp and scary. So we started off with pig squeals and other piercing sounds. But it soon became apparent that it was going to be too much and it also sounded too much like pigs.

We started to work in different vocals that were a bit lower. Eliot did some great work with these animal predator calls that he got. He performed them and pitched the recordings down and stitched them in different ways to try and get the main voice of the Trench.

It was around that time that Harry Cohen (sound designer at Twenty Four Seven Sound) was available and he gave us some of his incredible work. He gave us a bunch of sound source of monsters that we layered on there, to get a good sound for the Trench that was scary, big, and sharp but not too piercing.

For a while that scene was absolutely huge. It had a lightning storm happening, rain, huge music, and then these monsters. Once again James saved the day because he came in and looked at it and said, “Hey guys what if we take the music out of the beginning of the scene?”

When you strip the music out, suddenly the life was put back into these creatures and they became terrifying.

But we weren’t done yet. The visual effects were coming in more fleshed out and we started to get a sense of what these guys looked like. For months, we were working on the scenes with actors in big rubber suits stomping around on blue screen. We didn’t have any sense of what they were going to look like. The VFX came in and we realized that these were amphibious-type creatures. So we put a layer in there that was more amphibious and reptilian. We added different types of frogs and lizard sounds, sounds that were more guttural and more like croaks.

Eliot took those pieces and incorporated them into the predator calls that he was working with. Then we started to have this creature that was feeling more and more organic as it went on. Once they dive underwater, you have these great moments where the camera goes out to a wide shot and you just hear the music and a little bit of the storm. Then we cut in close and it’s like a hammer blow of screaming and the flare burning underwater. For that, we used those same creature sounds and frogs croaking thrown into Cargo Cult’s Slapper for a bit of effect. From that, we made this whole underwater tapestry and there may be a bit of reverb in there. It made the scene feel very real, very terrifying and also very unique with a creature you never heard before.