Field Report: Rock Destruction Sound Effects – Recording for Pompeii

Last fall I was fortunate to be asked to record sound effects for the Hollywood feature film Pompeii.

At a reported total budget of $100 million dollars, it was one of the most prominent films I have had the pleasure of being involved with. I was quite excited to contribute sound fx to help the sound crew tell their story.

I finished that project in the late autumn. Working on Pompeii was a fantastic experience. Since then, I’ve thought a lot about how unique that shoot was.

I wrote about the differences field recording for feature films last week. Today I’ll share how those ideas worked with Pompeii. I’ll explain how the shoot came about, how I completed it, and some tricks I learned that you can take away to help with your own field recordings.

Field Recording for Pompeii

I was contacted in the late summer last year by Stephen Barden, sound supervisor at Sound Dogs Toronto. You may recognize his name. He’s also a professor of Sound & Sound Design at Sheridan College. I wrote an article about his program a year ago, and also in an article about a field recording lecture a few weeks ago.

Stephen gave me the broad strokes of the project: he needed sound effects for the destruction of the Roman city of Pompeii.

And with that, I began my search.

Research: A Dramatic History

Research is first step of any field recording gig. Why?

No two sound effects are alike. Even similar ones have important distinctions that set them apart. This is true on a broad scope. Think about motorcycles. Cruisers are different from speed bikes, and dirt bikes. That’s obvious. But what about between cruisers themselves? They’re not identical. Some have larger engines, distinctive tailpipes, and varying acceleration. Only a handful will be suitable for your project.

Pompeii Street, courtesy of Paul Vlaar

Research discovers this. It helps a field recordist decide which sound clips to capture to support their project, and which to exclude.

The Roman city of Pompeii holds a unique place in history. It was founded next to the volcano Vesuvius. In 79 AD Vesuvius erupted (spoiler!), coating the city in a blanket of ash, suffocating its people, and burying the city in time. The film itself portrays the final days of the city as a gladiator (Kit Harington of Game of Thrones fame) races to escape the arena to rescue Cassia, the daughter of a wealthy merchant, as the city crumbles around him.

Research: Two Recording Styles

That info was a good start. But what about the sound fx themselves? Video samples weren’t available. I looked at photos and saw stone buildings and flagstone streets. What clips should I record? I approached it from two angles.

1. Helping The Crew. The first approach was to provide what would be most helpful to the crew. I imagined an ancient, noble city collapsing. That called for rock destruction, and lots of it.

   The best thing would be the real deal: a building crumbling. Perhaps demolition? A brief search didn’t find anything nearby. And it wouldn’t sound right, anyway. There would be construction vehicles, and too much metal.

   A family friend used to haul gravel across the province. They told me that a company a few hours outside of Toronto blasted limestone walls once a week. I looked into it, but involving the company and the additional costs was too complicated. In my experience, complex field recording shoots produce lifeless sound effects. I wanted more control than that.

   The best solution would be to perform rock destruction myself. I planned to record the elements: drops, breaks, and tumbles that the sound crew could assemble into larger compositions for the destruction of the city.

2. Imagination. This led to the second idea: imagination. Rocks are fairly easy to record. They don’t fight back. They’re predictable, and controllable.

   This is where the research of Pompeii and the film became incredibly valuable. Knowing history and the scope of the film explained the emotion. The sound effects needed to be powerful, thrilling, and harrowing.

   So, I wanted to capture the rock sound effects with intentionality. Why? Well, for my part, anyway, they would be the star.

   I planned to record the technical “scientific” takes the post crew needed. I also wanted to include takes with personality that supported the story and its emotion.

Scouting: Finding The Holy Grail

I considered recording in a Foley room. I quickly realized that wouldn’t work. First of all, I wanted huge, 100-pound boulders. Foley rooms don’t stock that sort of thing. Also, recording inside would shortchange the richness and distance of the space and air of exterior recordings.

But where could I do this? Southwestern Ontario is densely packed with crowds and air and car traffic. Recording outside anywhere within a four-hour drive from Toronto required working in the dead of winter at three in the morning.

I had been searching for a solution to this for years. How can an urban field recordist capture specific sound effects freely outside?

My idea was to find something that worked like a wilderness sound booth: an abandoned rock quarry. Why?

• Quarries are isolated. No cars would intrude. Crowds don’t visit rock quarries. I could work undisturbed for as long as I wanted.
• We all know how well sound travels across a lake. A quarry, by contrast, is sunken within the earth. A quarry would act as a natural exterior “room” that minimized wind and intruding sounds.
• Quarries can have amazing natural reflections. It depends on the size of the quarry and its surfaces, though. This can give a cool aspect to your field recordings. I also discovered a technique to avoid these reflections when I needed more intimate recordings.

So, the Pompeii shoot coincided with my search for my holy grail of exterior field recording locations. Up until that point I had had no luck. Even the most clever Google searches were fruitless. Then I had the idea to search for rock climbing locations. I looked specifically for non-certified spots, since those would be less travelled, unusual areas.

I also browsed Canada’s Ministry of Natural Resources to find active gravel pits and quarries. That would rough in the general area. I cross-indexed that with the list of climbing spots. The result? Eight locations within two hours of Toronto.

Scouting: Finding Character

I spent an entire day scouting the locations. Most were terrible. I was primarily hunting for an isolated location. There were too many people, and too much traffic, though. I was also searching for something else, too: character.

When I imagined the catastrophe, I pictured a buildings caving, crumbling, and crashing within the canyons of ancient streets. That gave me another idea: to include the environment as part of the recordings.

Most of the time we want to capture specific sound effects in isolation. We don’t want other sounds overlapping. The goal is to capture a pure sound effect, untainted by anything else. This is known as recording a sound clip clean. Why do we want this?

Well, clean sound effects are more useful. Other, overlapping sounds limit how your clips can be used. Consider, for example, a birdsong with a river in the distance. Since the river overlaps the bird, the sound of both will be audible whenever that clip is used. But what if your project doesn’t have a river? Then you can’t use the clip at all. That’s why it’s better to record the bird clean. Clean files are more flexible.

My idea, however, involved overlapping sound on purpose. In this case, the character of the quarry’s reflections would fit perfectly as reverberant rock destruction in the echoey city streets of ancient Pompeii. Both the rock props and the quarry environment would contribute paired voices.

So, I searched for a quarry that was isolated, and also sounded good itself. With incredible good fortune, I found a hidden pit about an hour outside of Toronto.

Here’s a short video of the location:

The Shoot

Challenges

While I knew about the project in August, I couldn’t shoot right away. There were too many insects and birds. They would saturate the recordings, making them completely useless.

There is an ideal window for field recording in Southern Ontario. It is between the death of the insects and the arrival of winter. It’s a narrow sliver of time, about four weeks. I watched the forecast, and waited for a clear day. During autumn the wind picks up, too, though. Very few days were still. I decided to strike out and record anyway.

That was a bad idea. While the location was good, the wind was so strong that the trees on the ridge above the pit remained incredibly loud. The day was a complete and discouraging wash.

I needed a day with better weather. The days were getting colder. Time was rapidly running out. I remained patient. I waited a week. Then, one day the weather turned.

It was an overcast, dank day. That was good. Hikers would be discouraged from visiting. And, most importantly, it was completely still.

A perfect day for recording.

Technique

I approached the shoot in two ways:

1. Set Up. I wanted to record the rocks differently. I thought about them as having not one, but two voices.

   Focusing closely on the rocks themselves was paramount. The isolated tumbles, falls, scrapes, and scratches would be the main tools the sound crew needed. That was the first voice.

   I also wanted to capture a second voice with each take: the environment. The cool reflections in the quarry would match perfectly with the echoey streets of Pompeii.

   So, I used a multi-microphone set up. I recorded each take closely with a narrow pattern to capture the tight expression of the effect. I paired that with a distant perspective to capture the reflections, in sync with the closer hits.

   Here are two shots. The first shows a few of the surfaces I used for the Foley. The second shows microphone positioning for rocks tumbling down the rockslide, which I hoped would layer to create the impression of buildings cracking apart and tumbling to the ground.

   

   A few performing locations

   

   Rockslide microphone locations

   
   

2. Articulation. I was recording rock sound effects. Surely throwing rocks around is easy? Well, that’s deceiving.

   Without seeing picture, I knew I had to provide as much coverage as I could. I’ve mentioned “articulation” in an earlier post. I used that to break down each performance by:

   • Rock substance. The composition of the rock I’d be manipulating. Granite, limestone, etc.
   • Surface substance. The rocks wouldn’t make any noise unless they met another surface. Did they hit other rocks, gravel, dirt, leaves, or a rock slab?
   • Rock size. I chose variations by both size and weight.
   • Performance. The most detailed aspect. The action or motion. I covered drops, drags, tumbles, slides, scrapes, breaks, and more.
   • Speed. Were they fast or slow tumbles? Gentle or hard?
   • Character. Adding personality and emotion to the takes.

    

   That list gave me ample voices to work with. Adding emotion and character added breadth after I completed the “scientific” takes.

   After a long day I returned home with thousands of takes.

Mastering & Delivery

File List – Short Takes

I mastered each hit separately. That was a lot of work, but I gauged that it was better than providing a number of hits in a single sound file. That style (known as a “series”) wouldn’t work for post editors. They need to audition samples quickly. A long series file with multiple takes meant they either have to wait for a track to complete to hear everything available, or scrub within the take. It’s far easier to audition short takes one after another, for example while browsing in Soundminer. Short takes are also more helpful for post editing: they can simply drop them into a timeline without needing to trim them first. I used sensible names to organize similar takes together.

Delivery Folders

I gave the post crew the original takes. That provided the building blocks they’d need for the edits. I also created a few alternative takes, or alts. I processed the clips with a specific slant to match an emotion. I used bass enhancement to create an ominous and fearful feeling. I created other takes with compression and transient modulation to add power and aggression. My thought was that most creative sound designers don’t gravitate toward specs and measurements. They work in the language of emotion.

Balancing Sound Effects Recording

So what can a field recordist take away from a shoot like this? One idea is balance.

It’s important to think about the needs of your audience. In this case, it was vital to ensure enough material was recorded to help the post crew do their job. We don’t want every take to be lifeless, however. That’s why it’s important to balance technical, scientific takes with imagination. This is your input. In most cases, it must be subtle. However, sound effects that are imbued with personality, character, and your own field recording signature give clips vibrancy and depth.

As field recordists, we often focus heavily on the subject itself. That’s certainly an important voice. It’s essential to capture that cleanly. There’s another voice, too, though: the environment. Often this can contribute a dramatic cast to the recordings, like it did at the quarry. It can be subtle, as well: the chaos of a gymnasium as schoolchildren yammer, or the lonesome echo of a dog barking in the mountains. Those sounds blend the subject with its environment around it to create a unique recording.

By arranging a balance between technical and expressive takes, between and a sound and its surroundings, your field recordings become full: they’re both helpful to the sound crew, and expressive, as well.

A Creative Arc

I mentioned that knowing your audience’s needs is essential to capturing good sound effects. It’s also helpful to know their perspective on the sounds, and the project in general.

So, what is a sound supervisor’s perspective on this? Sound Dogs sound supervisor Stephen Barden graciously shared with me his experience working on Pompeii, and his vision for a film soundtrack:

Paul sent this article to me to read before publishing and all I can say is that he nailed it! He nailed the recordings but also, just as important, he has very successfully verbalized in this writing that mystery which motivates us and inspires us in this crazy craft: How can we go about capturing and conveying sounds that help us in our storytelling efforts. All of the processes he described (cerebral and visceral) are those that we continually fall back on in the middle of nowhere when we’re recording but also when we’re sitting – alone – in our dark cutting rooms, hopefully selecting *just the right sound* and also when we’re putting it all together on the stage during the final mix. Ultimately, no sounds come out of those speakers by accident – we choose each of them and play them at a particular level and coming out of a particular channel for a reason. I hope the reader appreciates the thought and contemplative time that Paul puts into the creation of his libraries – his work is wonderful.

Thanks to Paul for putting together an outstanding, rich and detailed library of rocks for us. Our director, Paul W.S. Anderson, is not shy about sound: he likes his films to be loud. But, more than anything, he loves the smaller details that still shine through in his tracks. Paul (Virostek!) gave us loads of those details to play with. In particular, his high-resolution recordings gave us a great deal of flexibility for post manipulation.

Thanks for the ROCK and roll.

I’m grateful for Stephen Barden’s kind words. But, what about you? How can a sound supervisor’s thoughts help us when field recording?

Well, it opens our perspective. Field recording, in its most basic sense, is about ensnaring sound clips well and accurately. When your tracks are involved in a project, that job changes.

You begin by balancing your sound effect’s voices, and their articulation and expression. This is matched by your sound supervisor’s aim for the soundtrack: the careful reflection and section of tracks. It involves your director’s sonic preference for the emotional impact in the theatre. Field recording, and sound effects, join a project’s arc and, from that point forward, follow it through its crest to completion. You, your crew, and the soundtrack work together to contribute to a goal that is more than just a collection of clips on a hard drive: the goal to seam a project together to create an experience.

Many thanks to Stephen Barden of Sound Dogs Toronto!

To stay in touch, receive free updates by email newsletter or RSS feed.  |  Follow on Twitter, Facebook, YouTube, or SoundCloud.