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-   -   Cinema mixing levels poll (http://duc.avid.com/showthread.php?t=387744)

yoerik roevens 01-06-2017 08:36 AM

Re: Cinema mixing levels poll
 
Quote:

Originally Posted by Branko (Post 2405332)
Seems we quickly forgot some things from our recent history. Until the DCPs took over, we always lived with limitations, which is a true name for standards. Let me remind you:

While mixing for Dolby Digital (which has 20 dB of headroom over 85), we had to live with limitations - those of analog soundtracks (100% modulation was 6dB above 85) that served as a backup in case of DD failure during the playback in cinemas. Consequently, you could not make your mix louder than what was permitted by physical limitations of an optical soundtrack, because there would be a huge difference in levels, and "seamless switching" between analog and digital would be impossible. Dolby Consultants would attend print mastering sessions and assure this request was respected. The great difference between digital and analog was (apart from discrete surrounds and LFE) in transients.
Loudness wars started immediately after analog disappeared from our workflow - engineers were quick to fill the empty space above -20 FS and make "louder" mixes.

So, to recap, you cannot just simply go back to pre-DCP standards, because the conditions have changed, and there's nothing (and no one) to tell you where's the limit. As Cheesehead says, we need some new standards/limitations.

I agree partly, however, 'pre-DCP'-standards are still in place, although they're not updated for new audio formats. It`s just people not respecting them.
This is an interesting read: https://www.smpte.org/sites/default/...o-Vessa-v2.pdf

I agree calibration practice might need an update. But reference calibration is the only way to go in cinema. Loudness metering makes no sense at all. In the current loudness metering scheme roughly said (!!!) everything below the top 20 dBFS is ignored as being noise, which makes no sense at all. One could enlarge the loudness window/lower the noise threshold, but then the measured loudness makes even less sense.

joachim 01-06-2017 09:08 AM

Re: Cinema mixing levels poll
 
Quote:

Originally Posted by yoerik roevens (Post 2405366)
Loudness metering makes no sense at all. In the current loudness metering scheme roughly said (!!!) everything below the top 20 dBFS is ignored as being noise, which makes no sense at all. One could enlarge the loudness window/lower the noise threshold, but then the measured loudness makes even less sense.

When only the dia bus/stem is measured, it would be different/precise. (Like the dialnorm for AC3). Or ?

yoerik roevens 01-06-2017 09:38 AM

Re: Cinema mixing levels poll
 
Quote:

Originally Posted by joachim (Post 2405369)
When only the dia bus/stem is measured, it would be different/precise. (Like the dialnorm for AC3). Or ?

that would make more sense imo, at least for the majority of commercial films that are dialogue based. However, I'm not a fan of implying strict norms here. Especially not loudness norms. After all, dialogue levels also vary depending on style and context and using program loudness metering we might end up in situations where we have to remix an entire film (or large parts of it) when a director decides to last minute remove or add a scene. Also, not all films are wall-to-wall stuffed with in your face dialogue.

Steven1145 01-06-2017 09:38 AM

Re: Cinema mixing levels poll
 
Dialnorm is meant to be measured across a complete mix, it's the level of the mix in places where dialog exists. I was told once at a technical committee here in France that it would totally unpractical to measure only the dialog bus because the measurement sometimes takes place in the video lab where the separate stems are not available.

Steven1145 01-06-2017 09:40 AM

Re: Cinema mixing levels poll
 
Quote:

Originally Posted by yoerik roevens (Post 2405376)
that would make more sense imo, at least for the majority of commercial films that are dialogue based. However, I'm not a fan of implying strict norms here. Especially not loudness norms. After all, dialogue levels also vary depending on style and context and using program loudness metering we might end up in situations where we have to remix an entire film (or large parts of it) when a director decides to last minute remove or add a scene. Also, not all films are wall-to-wall stuffed with in your face dialogue.

Yes but as some point one has to place some faith in the mixers, and have them choose a number of scenes to make dialog measurements, not an Integrated measurement of the whole movie (which would not make sense as some films have hardly any dialog, others are wall to wall blab).

yoerik roevens 01-06-2017 09:50 AM

Re: Cinema mixing levels poll
 
Quote:

Originally Posted by Steven1145 (Post 2405378)
Yes but as some point one has to place some faith in the mixers, and have them choose a number of scenes to make dialog measurements, not an Integrated measurement of the whole movie (which would not make sense as some films have hardly any dialog, others are wall to wall blab).

Exactly, and that's the whole point, if we could restore faith in the mixers (who are often pressed by directors and producers to deliver bad/overly loud mixes), and theaters (who are often pressed by a tiny group of customers as well as bad isolation between the rooms to take things down) we wouldn't need any of that and could just go with a good reference standard again.
I think we all agree mixing and playback levels are going through some kind of crisis right now, but let's not panic and settle too quickly for bad solutions, like loudness metering (imo).
We're not gonna solve this today, but we must keep trying ;)

dr sound 01-06-2017 01:19 PM

Re: Cinema mixing levels poll
 
See this is what I question....
I can take any film for example that was mixed at
Sony Pictures
Warner Brothers
Fox
Disney
Universal
Technicolor
Formoss


and play them at "The Dub Stage" and they will all be in the ballpark.
Why, because all of them if mixed in a Feature Dubbing Stage at any of the above
Studios use one common thing.. A Calibrated Room at 85, 7 on The Dolby Box.
Now that is not to say some may sound different from other as we all know not everyone mixes Dialog the same, Music or SFX the same BUT they all mix at 7.
Personally I do not know anyone at the above studios that changes their monitor level. Now sure some of the lower budget movies that have a limited budget get mixed in small TV rooms or editorial suites and their levels are usually way off the mark but even those clients usually will playback the mix at a Feature Dubbing Stage to at least get a sense of how their mix sounds in a bigger venue.

This has been my experience.
My experience when I go to Audience Test Screenings that I mix that nearly always have Dolby Theatrical Engineers calibrate the room my mixes are right on the money. I have never adjusted the little orange remote box more that +/- 1 db EVER!
While I am at these test screenings we always do a morning "run through" to listen and check both sound and picture. We usually have 4-6 hours of waiting for the screening to start typically at 7:30 pm. With this free time I have access to the projection booth of the complex and it can have anywhere between 6 and 30 Theaters. I go by every room and look at the monitor box and not 1 is set for Dolby 7… NOT ONE! They are typically 4.5- 5.5, occasionally 6.
So if we use the Dolby Formula of 7= 85 spl
The Theaters are playing back:
4.5= 76 spl
5= 78.33 spl
5.5 = 80 spl
6.0= 81 spl

Now here is the heart of the issue:
We Re-Recording Mixers can’t get a proper translation when the
Mix we do is 9+ db DOWN.
What is the first thing that happens, the audience has a hard time hearing the Dialog, you know the foundation of the story. We loose their attention, their minds drift away from the story and the ability to connect with the actors on the screen.
This is a vicious circle that we need to find an answer.
If every theater played back the picture through a projector that was only 5ft Lamberts bright every Director, Cinematographer, Producer and Actor would be up in arms! The same thing is happening with our playback of the Sound Mix!
We need to find an answer.

Branko 01-07-2017 03:42 AM

Re: Cinema mixing levels poll
 
Quote:

Originally Posted by yoerik roevens (Post 2405366)
I agree partly, however, 'pre-DCP'-standards are still in place, although they're not updated for new audio formats. It`s just people not respecting them.
This is an interesting read: https://www.smpte.org/sites/default/...o-Vessa-v2.pdf

I agree calibration practice might need an update. But reference calibration is the only way to go in cinema. Loudness metering makes no sense at all. In the current loudness metering scheme roughly said (!!!) everything below the top 20 dBFS is ignored as being noise, which makes no sense at all. One could enlarge the loudness window/lower the noise threshold, but then the measured loudness makes even less sense.

Allow me to disagree with some of your points.
Standards were implemented and enforced by a company (Dolby), not by any government or other law enforcement organisation.
These were respected for two main reasons: 1. you could not go over without damaging the equipment and 2. In order to use the technology, producers had to sign a contract with Dolby, who was protecting their technology.
Let me explain further: when the reference level was set at 85 for 50% mod, it had to do with available physical space on 35mm prints. You simply could not go over max modulation, because Lt and Rt tracks would collide, full stop.
Most optical sound negative recorders were Westrex type, with string light valves. You go over - you burn them. That's 5000 dollars, and several days of downtime. That was how the standard was implemented!
When we switched to DAWs for editing and digital mixing consoles, it was a general consensus to adopt 20 dB of headroom, as that was available in most analog consoles. Having both analog and digital tracks on prints, the "levels standard" was still preserved. As a result, transients on analog tracks (gunshots, punches, slaps, door slams etc) sounded muffled compared to DD or DTS, but the overall loudness was set relative to analog mix. As I said in my previous post, you could go for another 6 dB over 85 for full modulation, and there was a space for another 3-4 dB before you burn the optical recorder.
In conclusion, there were 10 dB left, which you could not use.

These "extra" 10 dB are available now, so the "standard" is gone, and there's no point in respecting the standard, because it will not yield expected results.

If we want to have the situation controlled again, the calibration levels should be changed.
Why 85? Why not 87 or 82 or 79? Because it used to be "safe" when analog tracks were dominant.
Most of the audience's complaints are about extreme levels. We know these levels have raised by 10dB SPL when DCPs took over 35mm. It is a question of simply putting them back where they used to sit.
And we can also speak of increase in HF contents in modern soundtracks, if we want to broaden the discussion.

Frank Kruse 01-08-2017 05:59 AM

Re: Cinema mixing levels poll
 
See here:

http://duc.avid.com/showthread.php?t=329889

Gregor has written a very good paper about this topic some years ago with tons of measurements of films from different countries and genres.

Not sure if the paper or his results are public somewhere.

Maybe Gregor will chime in...

Frank.

joachim 01-08-2017 07:01 AM

Re: Cinema mixing levels poll
 
Quote:

Originally Posted by Frank Kruse (Post 2405672)
Not sure if the paper or his results are public somewhere.

Could be this one : https://opus4.kobv.de/opus4-filmuniv.../BonseDipl.pdf
It is in German.
If I understand this correctly, he measured the loudness of a lot of movies (absolute loudness of the master), than played those back at his personal playback level, some at Dolby 6, some at 5, some at 4, some at 7.5, ... (page 67).
The correlation of those values (e.g. Dialog LUFS of master measured is -27, but played back at 5, so correlated level is -27 LUFS + -6.6 = -33,6 LUFS) can be seen on page 68.
Dialog levels are close together.


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