I was watching the Bluray of 13 Hours: The Secret Soldiers of Benghazi that day, and I am wondering how to avoid killing headroom when mixing action scenes like those in the movie. There were gunshots, explosion, bullet/car impact and all of them had fast and strong transient. They were easily to be squished. But they were both punchy in the movie. Is it only because of good compression and limiting?
1 Answer
It's not so much that you compress to limit the headroom [although TV & Home Theatre releases can often be compressed because the full dynamic range of a theatre movie tends to annoy the neighbours]
What's used a lot of the time is the full dynamic range needed to present the highs yet leave the lows audible.
The centre speech channel is then balanced up to give a "standard" acceptable level.
This is done by adding a parameter known as DialNorm. This is in effect an overall volume control for the entire soundtrack that puts dialogue at a "normal" level & adjusts everything else accordingly.
I'm not even going to tackle the entirety of dialnorm & how it's done, because this article has more than it's possible to even précis here.
Home Theatre HiFi - Feature Article - "Dialogue Normalization: Friend or Foe" - June, 2000 (Updated August, 2001) Brian Florian