“Can we turn the subtitles on?”
When I’m at a party or in some gathering without a bunch of other audio people, someone will inevitably ask me about my profession. One of the most common things I hear, “Why do audio engineers always mix the dialog so quiet in movies?” This has led to write the article below:
Why Dialogue Feels Quiet in Movies
Is that heading too on the nose?
In common post production workflows (workflows for video content) the most common practice is to start with a mix for surround sound. Immediately you can probably see the problem here – not everyone has a surround sound system at home. So how is that surround sound mix “folding down” when played in stereo?
A typical surround sound format is 5.1. That means there are 6 channels of audio that are being played back over 5 speakers at ear level (left, right, center, left surround, and right surround) and one subwoofer. The sub handles all the low frequencies that the other speakers (or “satellites”) can’t reproduce along with any other low frequency effects (like a helicopter rumble for example.) Our laptops and TV’s only have two of those speakers – the left and right. Somehow, we need to fit those original six channels into just two – the left and right.
Are you still with me?? If it’s confusing don’t worry, it was confusing to me at first too, so I drew out what’s going on in a top down view.
So that’s you there on the couch facing the TV. You can see in the front you’ve got the left center and right speakers, and the rear surround speakers are behind you. So let’s start folding it down:
How a 5.1 Mix is Downmixed to Stereo
Step 1: The Easy Channels
Left (L) and Right (R): We leave them alone. Boom done!
Subwoofer (LFE): A lot of times this just gets thrown away, but sometimes a bit of it is mixed into the left and right speakers. Most small speakers can’t reproduce these frequencies though.
Step 2: Folding down the Surrounds
Moving on to the surrounds!
Left Surround (LS): This one goes into the Left (L), and we turn it’s volume down. Usually around -3 to -6 db.
Right Surround (RS): Super easy, we’re going to the same thing. Put it into the right (R) channel and turn it down in volume. Again -3 to -6 dB.
This keeps some of the ambience and atmosphere and effects from the surrounds without overwhelming the mix. Onward!
Step 3: The Pesky Center Channel (C)
Now here’s where it gets tricky… In surround sound, we send dang near all the dialogue down the center speaker. But in stereo we don’t have one. So what do we do?
The center channel audio is split equally between the left and right speakers.
To avoid overpowering the mix, it’s turned down by about -3 dB per channel.
Since our perception of volume changes when a sound moves from a single source (center) to two sources (L/R), the net perceived loudness drops by around -6 dB.
Beyond just lowering the dialogue, another issue comes into play: competition. In surround sound, music, ambience, and effects are spread across multiple speakers, giving dialogue its own space. But in stereo, everything is crammed into just two channels. This can make music and effects feel louder relative to dialogue, even though their levels haven’t actually changed.
So that’s what you’re experiencing. It’s not that audio engineers are turning up the music and sound effects while they turn down the dialog – it’s that the perception of the audio that was originally in the center channel is quieter in a stereo setting and all these music and effects are trying to find room in the same speakers.
Pretty crazy right?
So, Why Don’t Movies Prioritize Stereo Mixes?
So I imagine now you may be thinking, “If most people are listening to stereo on laptops or TVs, then why don’t studios make a dedicated stereo mix?” Well for two main reasons:
Industry Standards: Surround sound mixing workflows have been the standard for decades, and everything defaults to it. Changing this would require a major shift in how films are made.
Theater First & Home Later: Movies are made for the theater not at home. Movie makers can’t justify spending extra money on a dedicated stereo mix. On a $10-50 million film, only about 3-7% is spent on audio. They don’t have any wiggle room.
Movies are still a business proposition. They require a lot of money and people to make. (You’ve seen all those hundreds of names at the end.) Most often, they don’t make back the money invested and if they do, they rarely do more than break even. So, we have to make them for theaters first, because that’s where people pay for them.
Alright, so that’s it! When you struggle to hear dialogue on your TV, remember—it’s not that mixers are cranking up music and effects just to annoy you. Movies are made for theaters, where surround sound is the standard. A proper cinematic mix is designed for big speakers, a treated environment, and an audience that’s present. No auto-leveling, no distractions—just immersive storytelling the way it was meant to be seen and heard.
All that being said – home viewers are getting thought about more and more.. Technologies like Dolby Atmos are being developed to help bridge that gap, making immersive audio possible even on stereo systems. (Getting rid of that easy math we did and throwing in some really cool complicated math.)
That said… if you really want to hear a movie right—go to the theater. It’s worth the 10 bucks.