Quiet dialogue and deafening explosions!

Why dialogue is muffled and explosions roar when watching movies at home.

We’ve all been there: you’re start watching a movie at home, and the dialogue seems a bit low. You crank up the volume and continue watching the movie. Until an explosion or gun shot in the movie rattles your speakers and wakes up your neighbor.

This back and forth throughout the movie, turning the volume up and down, is quite an annoyance for many movie fans. “Were the sound mixers who worked on this film complete morons?”, you might wonder.

No, not at all. There is an explanation for why this often happens when watching movies at home, and there is (usually) a way to fix it.

“Movies are mixed to sound good in a movie theater, not the living room in your little one-bedroom apartment”

Sound mixing a movie for theater vs home

When mixing a movie (in movie terms, mixing is the work that combines all the sound elements — dialogue, effects, music — on a sound track and properly adjusts the volumes, among other things), most theatrical feature films are mixed with a 5.1 surround sound at the very least. In order for a movie to even be nominated for an Academy Award for sound mixing, it has to feature at least a 5.1 mix. Therefore, most theatrical films have at least a 5.1 mix, with many big budget movies having even more elaborate sound mixes with many more channels.

When movies are mixed, they are mixed to sound good in a movie theater, not the living room in your little one-bedroom apartment. The sound mixers and directors want the best possible dynamic range, and they mix for the best possible sound system: the sound systems in movie theaters. Unfortunately, this doesn’t translate well into a home theater with a simple stereo speaker setup.

In a 5.1 sound mix, the center channel (speaker) is mainly used for dialogue, while the surrounding four channels are used for various effects and other sounds.

However, a problem arises when a movie mixed at 5.1 is played on a stereo speaker system that most home theaters have. In that case, there is no center speaker, so the dialogue channel is mixed in with the rest of the sounds, which often results in lower dialogue levels compared to the rest of the sounds. In other words, when the surround sound mix is is downconverted to a stereo mix, dialogue often gets short end of the stick.

Quiet dialogue and deafening explosions!

“When the surround sound mix is is downconverted to a stereo mix, dialogue often gets short end of the stick.”

Rob Jackson, a sound mixer who has worked in the industry for 20 years, told Screenhead, “5.1 is the norm for most films, but often producers won’t do a stereo down mix, which is what’s really needed for a non-theatrical release”. He adds that online streaming services such as Netflix “do a good job at making their movies sound as good as possible, since people stream on a variety of devices, most of them with built-in stereo speakers”.

He continues, “Mixing down to stereo isn’t that difficult. You send out the dialogue to left and right channels and boost it by about 5db, depending on the movie. It still takes work, and it’s one of those costs that producers rarely consider, since it happens after the movie has premiered or sold or whatever. Rarely is anyone willing to put up money that late in the game to do a proper stereo mix”.

Jackson adds, “Another issue is that the DVD market isn’t what it used to be. Blu-ray sales are nowhere near where DVD sales were 10 years ago. So studios and producers have less incentive to make a proper home theater mix of their movies. But Netflix and streaming sites are putting some pressure on producers and distributors for proper mixes for their platforms.”

“Netflix and streaming sites are putting some pressure on producers and distributors for proper mixes for their platforms.”

Sound mixing station

How to mitigate the problem on home theaters

Adding a center speaker is usually the best route to go if you are willing to spend some extra money. An easier solution, and probably the first one to try, is to check the settings of your media player. Most newer DVD and Blu-ray players have a “dynamic range compression” mode, that reduces the volume of loud sounds and brings up the quieter sounds, which in this case tends to be the dialogue. It usually does a good job at downscaling a theatrical 5.1 mix into a stereo mix, where is evenly spreads the center channel dialogue audio to the left and right channels. Another feature found in a lot of DVD and Blu-ray players is “Dialog Normalization”, which brings out the dialogue in movies.

Most modern studio films ship with 7.1 or 5.1 mixes, and rarely do they include a stereo mix. For example, the Blu-ray editions of Prometheus and Gone Girl have 7.1 and 5.1 mixes, but no stereo mix, while Fight Club has a dedicated stereo surround mix, in addition to a 5.1 mix. It’s always best to check the movie settings to see what kind of audio options are available and pick the one that suits your home theater system best.

A typical 5.1 setup with the center channel used for dialogue.

A typical 5.1 setup with the center channel used for dialogue.

And if you have a 5.1 surround system and the dialogue is still too low, simply turn up the volume of the center speaker, since most of the dialogue audio comes from there. A good speaker calibration is key if you have a dedicated center channel.

Sources and external links

Written by on May 16th, 2015. This article is part of Screenhead .