What’s the Difference Between Sound Editing & Mixing?

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Sound editing and sound mixing are two jobs that go hand in hand, but can be performed by different people with a different skill set/expertise, or the same person.

The New York Times used the definitions in an article, “In layman’s terms, sound editing is about collecting the sounds needed for a film. Sound mixing refers to what is done after they are collected.” (March 2, 2018) I think this is a good basic explanation, but here’s more detail for filmmakers who may be working with both.

Before the Sound Editor/Mixer Comes Into the Picture

Backing up a bit, the sounds captured during a film shoot are referred to as production sound. For the most part, production sound is dialog, such as actors performing their lines, or an interview subject speaking. But, production sound can also capture production sound effects, like a door closing, someone taking a breath, and movement sounds (like cloth, footsteps, etc).

As a picture editor is working, they will assemble all the sound available from the shots selected. This is essentially the beginning of sound editing, because it’s taking clips of audio and moving them in time (with edits) to help support telling the story. If a picture editor drops in sound from another shot (like dialog, sound effects, or room tone), or adds a sound effect from a sound library, this is also very basic sound editing.

When the Sound Team is Brought In

Generally, a sound editor will start working before the re-recording mixer (or mixers). The main reason for this is so the mixer won’t have to redo work. Think of it like getting a haircut where the first “pass” is to do a general trim on everything, then comes the detail work and styling the hair. The trim is the editor, and the finessing is the re-recording mixer.

Usually once a sound team (or person) is brought in, there is a conversation between the teams (picture and sound) to talk about the general needs of the project. Ideally, there will be a spotting session (watching the whole project together) so the sound crew can find out what sounds are temp, what a director or editor really loves, what areas need help, and to share ideas. Who attends the spotting session from the sound side will depend on the size of the team. In major Hollywood films, it would be the supervising sound editor, who is basically in charge of all the sound editors, and a liaison to the re-recording mixers when it comes time to mix.

For a sound crew coming in to a project late in the process (after production and editorial), we have no idea what scenes might have been more difficult to shoot or edit, or what sounds you may have spent a lot of time on, or anything that was a problem. If there’s any creative sounds that need built out, this is the best stage to have that conversation: What do you like? What don’t you like? How do you envision this scene sounding? Sound editors are there to support and enhance your work, but the only way to really do that well is to have an open conversation about what you want (and don’t want). Not all filmmakers and editors have exact tastes for sound (or the language for it), but that’s where a skilled sound professional can really help. Even talking about moods or feelings can help a sound person start thinking about a sound pallet for the film.

What Does a Sound Editor Do?

Depending on the size of a project, there could be a single sound editor or multiple people. On major Hollywood projects, there are a lot of editors – dialog editor, ADR editor (re-recorded lines), Foley editor (added footsteps, cloth movement, props, etc), sound effects editor, music editors, and possibly more than one in each of those roles (especially sound effects editors). There could also be a supervising sound editor, who supervises the team.

In a smaller scale (like an indie film or short), there could be one editor who is responsible for all these tasks (and this person might be the mixer, also). They would edit the dialog (cleaning up edits, filling holes) and basically polish/clean up everything that came over from the picture editor. If there was any ADR or Foley recorded, the sound editor will edit it. If the music came over from the picture editor, the sound editor will do a pass to finesse edits. If the picture editor added sound effects, the sound editor may “sweeten” these sounds, either replacing with better sounds or supplementing to make the sounds from the editor as good as possible.

A sound editor works with sound from the picture editor’s sequence but placed into audio software. The professional way to do this process is through a format called AAF. For more on this process, see my article What is An AAF and Why Does It Matter?

What Does a Mixer Do?

To backtrack a little, the term “mixer” is used in two phases in the film process. During production, the person who mixes sounds on set is the production sound mixer, or sometimes just referred to as sound mixer. In post-production, the term for a person who mixes sounds is re-recording mixer. Even though a re-recording mixer mixes sounds, professionals generally don’t use the term “sound mixer” to refer to post-production sound (only production). On major Hollywood projects (tv and film), there can be two or even three re-recording mixers on a project. The terms for production and post-production do commonly get confused, so if you’re looking for one (or the other), make it clear whether you’re looking for sound for production or post-production.

The re-recording mixer is responsible for taking all the edited sounds and balancing them against each other. The reason for this is pretty obvious if you’ve ever done a temp mix in the edit bay – music tracks come over blazing hot and dialog levels can have a huge range if an actor is whispering and screaming in the same scene. Take into account there could be a lot of different sound editors working independently – Foley, ADR, dialog, sound effects, music – that could be 5+ people working totally independently and the materials don’t come together until the re-recording mixer (or mixers) receives it all. On larger scale projects, there is usually some time set aside for predubbing, or doing an initial pass to get some basic balances in place.

Why Hire Professional Sound Editors & Mixers?

There’s a few reasons to hire a professional (ie, someone with at least some professional experience in post-production sound):

  • Audio editing software has a lot of capabilities that picture editing software does not. We have a lot of tools for crossfades, editing at the subframe level, etc that allow us a level of detail that’s not possible in the edit bay.
  • Professionals will have equipment and software geared towards having the highest quality possible. To gather all the common tools, it adds up – and it does take time to learn them all to the point of proficiency.
  • Professional sound people have trained ears to hear things that even a good picture editor or director will probably not be trained to notice.
  • A professional sound crew will be thinking ahead in the process. Is it a film for festival submission, or a mix for television? Will it be going to a foreign market? Distribution deals means technical specs that have to be met. Professional sound editors and mixers know this process well, and automatically work with this in mind. That can save a lot of money from having to figure it out down the road

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