Movies are frequently accused of being too loud, assuming the theater exhibiting said film played it at the correct level (has anyone ever hear of a theater playing a film above reference level?) Loudness is beholden to, among other things, dynamic range or the distance between the loudest and the softest sound, very much like photography, where dynamic range is defined by the distance between the brightest white and the blackest black.
There are a number of reasons for any given film having a wide or shallow dynamic range. Dynamic range has technical limits as well as aesthetic ones that include what a cinema can reproduce vs what a home theater or television can reproduce and that will affect every showing of a film and how it is heard.
Almost all theatrical film mixes are remixed for home video utilizing a variety of techniques to limit dynamic range and overall loudness. That being said, there is a community of filmmakers, including Jim Cameron, who bristle at this idea. It’s seen as an abomination to change the filmmakers intent and many, like Cameron, insist on dual inventory for the audio assets as well as encouraging the audience to select the “original” mix on their Blu-rays.
Sadly for films, the streamers and broadcasters are the keepers of their artistic legacy and heritage….because most films will NEVER be seen in a cinema after their initial release. Should we, as cinephiles, accept compressed image files and compressed audio simply because the broadcasters and streamers can’t manage bandwidth or audience peccadilloes? For the purists, like myself, I loathe the idea of dumbing down a mix for the home. The ideal situation would be one where the streamers/broadcasters (and Blu-ray producers) offer BOTH versions, un-altered cinema original and home-theater dynamic range reduced, as options to choose from when viewing. It’s a shame for those that have high quality home cinemas and want the dynamic experience of original audio but cannot hear it. There are a few boutique services that are offering original masters as a streaming/download option now. But very expensive and unlikely to penetrate the consumer market.
That being said, all the Studios and streamers define the parameters of a Home Theater mix with varying standards to adhere to in terms of average loudness and overall loudness (peak loudness) to control dynamic range in an attempt to achieve a balance between artistic intent and the needs of the Home Theater environment. Which is to say, it is an accepted axiom that most Home Theater consumers do not like wide dynamic range, the culprit that causes them to chase the volume on their remotes. I get it…but I don’t like it.
One of the ways dynamic range control is achieved is by remastering the original wide dynamic range mix at a lower monitor volume and remixing to “make-up” the lost volume and, at the same time, “limiting” peak volume through careful mixing or dynamic range limiting tools to achieve a flatter sound. Every re-recording mixer has a different way of approaching this. Some build exotic cocktails of compressors and limiters to control dynamic range, others do it all by hand, manually reducing loud audio peaks or extended loud sections of music and sound effects. There is no right way to do this.
The differences can be dramatic. Theatrical cinema is monitored at 85dB SPL as a standard. Home theater mixes are done at anywhere from 82dB SPL down to as low as 78dB. At 78db, one is more than half a loud as the original. This, effectively, reduces the dynamic range by 7dB, which can, in extreme cases make a gunshot no louder than someone shouting. Imagine losing a full stop of exposure to your image master after having composed your imagery for a wider dynamic range? Suddenly that shot under the table, where the antagonist pulls a hidden gun out of his coat intending to shoot, is now just a blob of black, lacking in detail. Ughhhh!
