Broadcast Levels/Compression

[Nomados]

I'm currently editing a film recently shot in Baghdad. We are also doing a temp mix for festivals and are trying to make do with the tools we have at hand.

Our source material is clean, but leans towards the loud side. helicopters, Humvees, loud voices and gunfire all contributing to very hot recordings.

We'd like to retain that loudness, while having a wide dynamic range--a smooth transition from a prayer call to a throaty five ton truck.

What I'm looking for our general rules of thumb for broadcast and theatrical levels. The emphasis for now is on broadcast.

What is the maximum acceptable peak and a good mid point for dialogue--measured on digital scale?

Next, I'm wondering if it is common to apply mild compression when mixing a doc of this nature--a way to bring out voices and get some throat out of the exciting bits. Or, is it better to just leave it natural?

An example would be a shot in checkpoint bunker where soldiers are speaking over low traffic, plus we have gunfire popping in and out--we'd like to get the gunfire prominent, without raising the overall level.

I appreciate any help with these questions.

[Tom Backus]

Here in the states I can tell you how most broadcast setups are. I mix to a Digibeta master with my peaks being no more than -10dbfs. reference tones line up at -20db = 0vu on the digital scale. Broadcasters typically have their transmission limiters clip at +8db.
Seems like alot of networks will reject a track if audio hits peaks over +10db above reference tone.

Keep in my mind this is only concerning broadcasts here in the states, things may be different for your purposes.

good Luck

Tom

[jayrose]

That -20 dBFS tone, -10 dBFS peak is often written into production contracts in the US. (I've had production companies ask what the heck it means.)

If you're going for broadcast, processing is essential. Between most tv sets and the background noises in living rooms, you've got a very narrow window. I use multiband on dialog, keeping it around -10 more or less, and then multiband on the entire show.

Since all the processing (in fact, everything in my studio) is in the digital domain and I'm careful with time constants, it doesn't get fatiguing.