Sound Mixers: The Unsung Heroes of Trailer Editing
Let's talk about sound mixing! Whether in movies or trailers, the sound mix is typically the last part of the process; it's the finishing touch that really ties everything together and makes the piece sing. When I was an assistant editor at the prestigious NYC movie trailer house Giaronomo Productions, some editors would get to fly to Los Angeles to attend/supervise the final sound mix.
The gulf between an editor's sound mix and that of a professional mixer can be vast even if it seems subtle at first. When one of my trailers has been professionally mixed, everything FEELS clear, and somehow EVERYTHING sounds big even though though intellectually I know it's impossible for everything to be loud at the same time and there's a lot of give and take in a sound mix. It's certainly MUCH more than just adjusting the volume of dialogue, music, and sound effects.
Practically speaking, sound mixing comes at the end of the process because if changes are made to the edit after the sound mix, it's INCREDIBLY TEDIOUS to adjust the mix. Just think, if one shot is suddenly two frames shorter or longer, everything after that shot has to be adjusted. If a second shot is the same length, but the action within the shot happens sooner or later, everything has to be further adjusted. If THREE shots... (you get the idea)
So what is sound mixing? I enlisted the help from a couple colleagues for this newsletter. Michael Cardillo of Creative Waves, who's mixed trailers I've made for Empire of Sin, Psychonauts 2, The Anacrusis, and more. And Gordon from A Shell in the Pit whose team makes game trailers and also sound design for games!
Michael mixed this trailer I made. I'm always impressed when a trailer balances dialogue, sound effects, music, and singing!
What is sound mixing?
Gordon: Sound mixing is the final stage of producing the sound for a trailer after sound design & editing. It’s ensuring that the viewer is focusing exactly where we want them, and feeling how we want them to feel, while still maintaining a soundscape that feels dynamic, full when it needs to be, spectrally balanced, free of painful frequencies, and interesting.
Michael: When sound has multiple “layers” you hear them all the same and at once. Mixing is making each sound (or “layer”) fit into the overall soundscape without overpowering the others. Decisions are always being made about the auditory hierarchy and how to get everything heard.
Think of a rock band which has: a bass player, a lead guitar, a drummer and a singer. In a rock song everyone is typically at the same time (and sometimes there are solos). But even when everyone is playing there are going to be times where one performance is more key. For example: if the lead guitar has a cool riff, there's a series of cool drum beats, or the vocalist has a big moment. The sound mixer has the power to make sure people get their moment to shine. When it's time to make one member heard most clearly, while the rest are put in the background (but still heard)
Another Michael mixed for me. There are a lot of moments in this trailer which I wanted to feel big (like the music after Raz says "Here goes nothing!," but I knew I couldn't make big until I asked Michael to make it so.
This is what Michael mentioned about hierarchy. In a sound mix the lead sound or combination of sounds is constantly changing. It's no good for everything to be at the same volume all the time; that would create an absolute cacophony with no focus. Also, it's no good to simply make the lead the loudest and everything else near inaudible. There's a balance to filling in the audio spectrum while ensuring the most important sound at any given moment is what people are focused on.
The first thing you think of when sound mixing is probably audio volume (if you want to get super deep into sound, "loudness" is another more subtle, but related factor). Volume is usually the main thing editors worry about. For example, they'll lower the volume of music when someone is speaking, and bring it back up when they finish.
An even more advanced aspect of sound are adjusting audio frequencies via equalization, also known as EQ. Every sound occupies a certain range of the audio spectrum. Think of the vocal ranges of humans (though these certainly do not cover the range of frequencies humans can hear). The basic ranges are: bass, baritone, tenor, alto, soprano. A bass has a very deep and low voice like Patrick Page from Hadestown and a soprano has a very high voice like Audra McDonald. Since each fit into their own pocket of the audio spectrum, they can to some degree be singing simultaneously at the same volume but both be audible.
Sound mixers also have the ability to adjust the volume of audio frequencies within one sound to carve out space in the spectrum for other sounds. So for example, they might lower ONLY the audio frequencies of the music which the singer occupies to free up some space for them. Whether it's the low end for a bass or the high end for a soprano, or something in between. With just volume and EQ there is A LOT a sound mixer can do to ensure the right thing is heard.
I'll let Gordon and Michael back in, but this was some audio basics I thought it was necessary to clear up first.
Michael's mix in this trailer helped give a great sense of the space. For example, the reverb of voices helps you understand how far away they are.
What is a dead giveaway indicator of a poorly mixed trailer?
Gordon: #1 would be that you’re straining to hear something you want to hear, the primary culprit being unintelligible dialogue buried in loud music or SFX.
More elusively, a hallmark of a poor mix is when a trailer leaves you feeling underwhelmed despite exciting, high-quality visuals. This likely will extend into the other aforementioned disciplines, however, and can’t solely be placed on the mix. Missing or too-quiet SFX detach the viewer from the experience on screen and make the activity less memorable. A mix that lacks dynamic, punch and breathing room for important moments can also have a very deflating effect–“If everything’s loud, nothing’s loud”. This of course depends on the format of the trailer itself–gameplay trailers and narrative or cinematic trailers all have very different mix requirements, varying from genre to genre.
I recently watched two trailers which have glaring sound mix problems. Coincidentally, they're both for games which involve giant epic battles. The first is for Thrones of North which has a lot of sound mix problems especially when the music kicks in towards the end. And the other is for Total Accurate Battle Simulatorwhich has a problem with very low music and very loud sound effects. Most trailers' mixes don't have problems quite this glaring, but it does happen! The effect is the trailer will look/feel lower quality or even worse, like it shipped before it was finished.
When I first watched this, towards the end I thought I had another browser tab open with music playing which was interfering with the trailer. Turns out it was just the trailer's mix.
When/why should someone consider hiring a sound mixer for their trailer? Is there a certain level of complexity, number of audio tracks, or types of audio which need it more?
Michael: Even a trailer that’s just voice over music could benefit from the experience of a good mixer, but when you get more than two elements at the same time, it’s critical. The more audio sources you have playing at once, the more likely that they are interfering with each other and need a critical ear to bring them all out.
Even little things like, “I wish that cello part in the music would make me cry more” or “Can that sound effect punch through a little more?” Another great advantage to having someone else mix it is that the editor already knows everything about every frame of video. Someone watching for the first time does not. When I mix, I use sound to draw attention to visuals that may sometimes be overlooked.
Gordon: I’d say that cinematic and narrative trailers require a more nuanced ear and advanced skillset than simpler gameplay trailers, which are often comprised of in-game SFX, a music track and a few whooshes and slams. Cinematic trailers usually require complete audio edits from the ground up which, when we’re finished with them, can run well over 100 tracks. Film post audio mix sessions are often over 1000 tracks–often dialogue alone can take up more than 100 tracks once all production, ADR, walla and voiceover tracks are incorporated.
I’d also recommend professional treatment when working with voiceover & dialogue, as dialogue requires a lot of finesse to sound professional. We like to clean all the lip smacks, ticks & pops out of the voices, balance them spectrally and compress/mix them to be consistently intelligible, and put them in the space with reverb/delay as needed.
This trailer was mixed by Power Up Audio, and is one of the first times I thought "WHOA" after one of my trailers was finished.
What’s the most useful/helpful thing an editor can do when sending a sequence to a sound mixer? For example, a method of organizing audio tracks and clips, labeling, file formats, or anything else
Michael: All of the above! Track organization can really help find the right sounds and get into the mix quicker. Communicate to the mixer about which sounds might be placeholders and which are beloved. The best thing to do is just start sending your projects to a mixer and you will quickly develop a rapport and things will start going smoothly in no time!
Gordon: We’ll want you to send us an OMF which allows us to open your audio edits from your video editing tool in our audio software. Have all tracks labeled with what’s on them, and don’t mix & match your tracks. A track labeled “dialogue 1” should only contain dialogue, ideally one character per track as each character will need their own processing chain.
Tracks should be grouped in kind. For example: all 4 tracks of dialogue together at the top, all SFX next, followed by foley, gameplay FX, ambience, then music. Doesn’t have to be in that order, but just make sure that your talking pink bunny doesn’t have dialogue on tracks 1, 5 & 17 for no apparent reason.
The timeline for my Uncharted 4 fan trailer (which was not professionally mixed, so if you want to listen to an epic trailer mixed by an editor who is not a professional mixer, this would be it. Some dialogue here and there is much less audible than I'd like.
In this timeline the first track is for dialogue, the next two are for music, after that are the in-game sound effects, and the last tracks are trailer sound design
What is an example of a trailer or piece of media which has really good sound mixing? (Michael was unable to finish answering the questions before this got posted, so the rest of these are just from Gordon. I'll update the blog version of this with Michael's answers in the future!)
Gordon: Say what you want about the film, and perhaps the format is getting a bit tired, but one of my favourite trailers of all time is for Ridley Scott’s Prometheus. The mix puts laser focus to what the trailer creators want us to be paying attention to. When the dialogue lines are important, the music/SFX are dropped dramatically to ensure we’re hearing those important story points. When a weird creature is the focus, that’s pushed to the forefront of the mix despite its on-screen movements being minimal.
By the time it reaches its climax the content of the dialogue matters less than the tone of their delivery, so the mixer is pushing the music & repetitive SFX much harder and, in a move of 7-dimension audio chess, dialogue intelligibility is cast to the wind for a few lines because it supports the tension & discomfort they want us to feel as everything goes off the rails. Expertise is knowing what the rules are, and knowing when to break them and this trailer does it wonderfully.
Are there any resources you’d recommend for someone who is interested in learning how to sound mix?
Gordon: This is a tough question as mixing is one of the more nuanced & advanced skills in the audio space, so it’s not typical to jump into learning explicitly. It requires a working (though not necessarily expertly professional) knowledge of recording, editing, sound design, dialogue editing, psychoacoustics, music mixing & editing, and all the tools required to manipulate all of that stuff and deliver it to the correct technical standards. It also, more importantly, requires a directorial sense of how to use all those tools to a specific emotional effect.
Post audio mixers in film work their way up from the bottom. Games are a much more casual format so everyone’s doing a bit of mixing here & there, with no one dedicated solely to it. It is something you learn as you’re learning the rest of the disciplines. There are sound designers/editors who may not mix, but there are not many mixers who don’t know how to edit/sound design.
That said, 90% of mixing is asking yourself for every scene “am I directing the viewer’s attention correctly?”. If no, then turn something down that’s in the way of what you’re hearing. Turn up what you want to be hearing if you have to. We use the ears to direct the eyes.
I went to Vancouver Film School and got an excellent education there. I don’t want to simply recommend an expensive school to everyone, though (I went on scholarship), so one esoteric resource that improved my mixing dramatically which is free is this oddball PDF, built from an extensive series of forum posts by an experienced and mysterious engineer going by the handle “Yep”. They are a fantastic writer and explain many of the concepts and tools required for mixing in very relatable and understandable ways. Now that you’ve reminded me of it I think I might even go review a few sections!
I’d also recommend a lot of conscious media consumption. Don’t just watch/play something, watch it a few times and take notes. How is the audio affecting our focus? What’s it like when played silent? What are the emotional takeaways? Would you change anything? What’s the ambience doing (if there is any–often skipped in trailers, while never skipped in film)? When is music loudest and why?
This is one of my first trailers I edited at a game trailer house, and I remember how much fuller the voices and all the audio felt after we received the mix.
If you were assigning homework to a sound mixing student, what would your first three lessons be?
Gordon: We’d have to be working from an existing skillset. We’d assume they know the basics of editing, design, and the audio anatomy of a linear piece. This is off the top of my head so is probably not perfect but:
I’d have them do an analysis or two like I just mentioned in the last answer.
We’d do a deep dive into the importance of dialogue intelligibility, and techniques to ensure it. “Dialogue is king”.
Probably session layout and planning, and how we’re grouping our different effects before launching into a hands-on mix project.
Is there anything else about sound mixing you’d like to share, or for people to know?
Gordon: I’m not a TV/Film re-recording mixer but feel the need to defend my colleagues working in that space because it’s one of the few places I see not-infrequent vitriol from the public towards audio folk: if you’re annoyed at your TV for the SFX/Music being too loud and the dialogue being too quiet, don’t get mad at the mixer! They’re just following orders, and were mixing in an ideal acoustic environment which your room is probably not. Engineers can’t mix for every possible listening environment. It’s also possible the production did not budget for a home theater mix so you may be listening to a theatrical mix, and your living room isn’t a theater.
Go into your TV or receiver’s options and see if they have a “night mode” or “boost dialogue” mode, or something similar. This will compress the overall mix so that the louds are quieter and the quiets are louder. It would sound garbo in a properly tuned space but will likely keep you from reaching for the remote as much. We have to default to mixing for tuned/treated spaces because you can always add more compression to an audio signal but you can’t un-compress it once it’s baked in. Kind of like un-cutting your hair.
I don't know how this mix compares to others, I just love this trailer. If you haven't seen this movie yet, you should.
Phew! Thanks for reading this far. But I hope you come away with a greater understanding and appreciation for sound mixing. It is kind of like the last edit to the trailer as well as the last bit of polish that makes it absolutely sing. Not every trailer necessitates or has the budget to hire a sound mixer, but at a certain level of experience, you owe it to you and your work to get help!