In a perfect world, the best visual takes would always align neatly with the best audio takes. But let’s say an actor’s focus on delivering the intensity of her facial expression causes her to slur part of the line that goes with it? Or not to be too hard on this otherwise excellent actress, let’s say she nailed the line flawlessly, but the microphone just wasn’t close enough to capture it. If you want to use that awesome take, you need to find a more articulate dialogue clip to go with it. The dialogue editor will hunt through every version to find one that synchs the audio and video perfectly together. At the same time, any off-camera or ambient noise such as the natural shuffling and rustling of the crew gets removed in this stage of the sound mix. If all this fails, the dialogue editor moves on to automated dialogue replacement (ADR); for fans of martial arts movies, this is a lot like dubbing, but with the same cast members actually trying to synch up to what’s on screen. In the ADR process, the actors re-record their lines in a studio to eliminate any audio problems and potentially improve their performances. Of course, ADR dialogue can run the risk of sounding totally unnatural for the somewhat noisy world where your story might be taking place.
As with a lot of other technical post-production work, sound mixing only really gets noticed when things go wrong. We’ve probably said this before, but sound problems are way more annoying to audiences than sub-par image quality or imperfect shot composition. Good sound designers and sound mixers pride themselves on being neither seen nor heard – well, actually, only on being heard without audio interference. The art of the audio mix requires process and subtlety in equal measure. So what’s the reward for all this? How about not alienating your entire audience and allowing them to appreciate your project on its own merits.
STEP ONE - Dialogue | VO | ADR
STEP TWO - FX | Foley
If you’ve taken an intro film course or read any film theory, you might know that diegetic sounds are any sounds happening within the world of the scene. For anyone who’s never come across this term, you can knock your pretentious cinephile friends down a peg when they try to talk over your head. Here’s an easy way to think of this concept as it applies to post-production: if you see a sledge hammer hitting through a wall, you expect a “booming” sound to accompany it. However, if you’ve ever been lucky or crazy enough to film a sledge hammer hitting a wall, you probably didn’t get that thunderous boom everyone imagines. This is where sound effects come into play. A sound FX person will try recording almost anything that might get that desired crash/boom sound for the shot, and then mix the best version into the audio track. Of course, not all diegetic sounds need to be visible on screen – they can also be implied. Think about any scene where a character being followed hears footsteps. Those footsteps probably weren’t recorded during the actual take; in fact, they might not even be actual footsteps.
STEP THREE - Music Mixing
So you managed to get the killer song or bombastic original score for your project. Nice work! Now, you want to make sure that the music doesn’t drown out the sound on screen. This may sound simple, but think about trying to listen to your friends talk when you guys are listening to music in the car. If it’s too loud, you can’t hear a damn thing, but if it’s too soft it’s distracting; to get the right mix, you probably fiddled around with the volume control, raised your own voices or met somewhere in the middle. For your project, the audience won’t have the ability to control the music mix, so it’s important to make sure the dialogue, diegetic sounds and soundtrack all blend together perfectly. You don’t want that great John Williams-esque fanfare drowning out the moving dialogue your writers wrote and actors acted.
STEP FOUR - Final Mix
All right, you’re basically done with the audio mixing. The last stage is putting all those now perfectly recorded and blended sounds together so that audiences will be able to hear them nicely. You can think of this like crossing your t’s and dotting your i’s, particularly if you imagine how hard it would actually be to understand something that were written with t’s un-crossed and i’s un-dotted. If you’re mixing in 5.1, which is standard surround sound, you’ll need to export the audio tracks to each channel (left, right, center, left-surround, right surround), as well as the stereo left/right mix and music and effects (M&E) mix. This sounds a little complicated, but a good sound mixer should know how to do this. This is also why everything we hear in theaters, home stereo systems or our overpriced headphones has such awesome sound quality these days.