By Mandi Bierly
Updated May 08, 2013 at 09:07 PM EDT
Marvel Studios
  • Movie

With Iron Man 3 officially kicking off the summer box office race, it’s only fitting that the film also launch our new series Sounds like a Summer Movie in which we find out how the sounds that bring blockbusters to life were created. In the case of Iron Man 3, it involved stealth recording at Toys ‘R’ Us, a visit to the firing range, and some remote-controlled jets. Warning: light spoilers ahead.

“The most important sound of the movie is going to be the sound of the suit because it’s Iron Man,” says supervising sound editor Mark Stoeckinger, a three-time Oscar nominee for Face/Off, Star Trek, and Unstoppable. “Metal is usually harsh and grates on people’s nerves, but the fact is, there’s a lot of it in Iron Man, so you’ve got to find a way to make that interesting. So we just recorded a lot of various metal objects and mic’d them in certain ways, filtered and processed those recordings so they weren’t just bright and edgy, and used all sorts of plug-ins to help make a lot of different notes like a musical instrument.”

His team got particularly creative for the servo sounds (the power actuators that move Iron Man’s suit every time he moves). They went out and recorded radio-controlled jets both flying and stationary. Even more fun: “You know how little kids have those little electric cars that they’ll get in and go about two or three miles an hour? When those aren’t running, if you take the wheels and you rock ’em back and forth, they kinda make that err… errr servo sound. We didn’t really want to buy one, so we went and looked at Craigslist for ones that people were looking to give away because they weren’t working,” Stoeckinger says, laughing. “Our first foray into that,” he admits, “was going into a Toys ‘R’ Us late at night when nobody was paying attention and recording some of them on the display wall, just to get an idea of what we wanted. Some of those sounds were more for the leg sounds — the legs of Iron Patriot. You just record a whole palette of that, like, ‘Ah, I think that will be good for that.’ ‘Yeah, that might be good for this.’ There was a lot of trial and error.”

Visually, the various Iron Man prototypes (or marks) who come to Tony Stark’s rescue in the climactic scene were different, so sonically, they’re unique to a certain point, too, Stoeckinger notes. “Each suit had its own schtick, so to speak, and whatever that was had to be accentuated,” he says. “Yeah, they have to sound like big metal, but you find, like, a helicopter startup wind sound for the Hulkbuster that runs in and holds up the crane just because it has a long tension build, almost like a piece of music.”

Experimentation was also called for when the team set out to capture sounds for the house attack. “Being guys, we gathered some firearms and went and rented a range and a bunch of microphones and got all sorts of different things to shoot at. We brought stone remnants, metal plates, unfinished propane tank ends, glass, bricks, tree stumps,” he says. “We played like kids, so when your child asks, ‘Dad, what did you do at work today?’, it’s hard with a straight face to be serious and do their math homework.” Recording sounds for Iron Man’s suit coming under heavy fire was a bit like a comedy sketch, he says. “Because a big boom is all you hear — the sound of the gunshot; you don’t hear the sound of the metal you’re trying to record,” he explains. “Long story short, we found little, almost pathetic .22 rounds that you could barely hear the bullet, and if you got close enough to what you were shooting, it all became one sound event. So instead of a ba-boom, it was just a ping.”

Once they had those sounds, they had to make sure we could hear them:

Stoeckinger says another fun scene to work on was the Air Force One rescue, where Iron Man saves 13 people who’ve been sucked out of the plane:

One of the more difficult sounds to figure out was the sound of Extremis:

As anyone who’s seen the film can attest, “There weren’t really any moments of pure silence,” Stoeckinger says. “But there were definitely moments of subtlety in the film.”

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Iron Man 3

  • Movie
  • PG-13
  • 129 minutes
  • Shane Black