Monday, April 28, 2014

Mixing too quiet means mixing too loud

If you're not trying to be really obnoxious to your office-mates you might think that it would be better to mix with your monitors turned down to a reasonable level. It's not. Indeed it means you have to mix over again.

In film there is a standard for how "loud" you should mix. Specifically, your monitors should be at 85dB SPL (measured in noise bands) from each speaker at the mix position with the meters at -20dB Fs. Does that make sense?
This is actually pretty loud. Louder than what you should be doing with music actually (my rule with mixing music is that you should be able to talk over it comfortably. That's how you know you're at about the right level.) Now the other thing with film mixing is that you typically have to hard-limit each channel at -12dB Fs. This may be more of a broadcast issue actually. But considering that -12dB Fs is 93dB SPL from each speaker it's a good idea to not go above that level anyway.
As an aside (isn't this entire post an aside?) I've often wondered why they fellows at Dolby or whomever decided to lose 12db of headroom from mixes. My only guess is that if all six channels of a 5.1 mix are limited to -12dB it becomes very hard to actually go above 0dB Fs when you mix all those channels together, even if you do it clumsily. That's my guess.
Anyway, remember about how 85dB SPL should equal -20dB Fs? Well even when I'm mixing "correctly" I don't even go that loud. I set my system to 72dB SPL at -20dB Fs. This makes mixes "louder" than if I'd done them at 85dB because I'm pushing the faders up more to make up for the fact that my monitors are turned down.
But this whole complaint is that I'd mixed the first pass of the Dead Residents movie even quieter than 72dB (somewhere around 60? Maybe?) and all of those mixes just slammed into those -12dB limiters way too often and too hard, losing any sort of dynamics in the mix and actually making it a bit distorted.
So, mixing quieter means mixing louder. Right?
Somebody re-write this so it makes sense.

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