Loudness Meters different in 5:1 mix

James Moore wrote on 1/6/2020, 4:36 PM

I did a stereo mix and kept the integrated LU using the Loudness Meters (EBU R128) from peaking past 0. I have never had a broadcaster reject audio mastered like this.

I am now doing a 5:1 mix of that track. When I simply change the project to 5:1 sound from Stereo and assign my output channels appropriately the Loudness Meters (EBU R128) indicate the mix is to hot - the integrated meters peak above 0 at 5.0 LU

Why is this? Is it a bug? Is there something different in how the Loudness Meters work in 5:1 versus Stereo resulting in signal that is too hot? Do I have to relevel the whole film to keep it 'legal'?

Any advice would be appreciated.

Thanks...

Comments

adis-a3097 wrote on 1/7/2020, 5:22 AM

How exactly do you assign your output channels appropriately? Don't you do stereo=>surround upmixing first?

What's your monitoring level when mixing 5.1?

James Moore wrote on 1/7/2020, 8:40 AM

Hi Adis, thanks for your comment.

I am unfamiliar with "Stereo=>upmixing" I didn't see any reference to upmix in the Vegas help file. It does talk about down mixing but that is to go from 5:1 to stereo, or stereo to mono.

By assigning appropriate channels I was referring to the assigning the output from the surround master to my monitoring channels.

To easily see what I am referring to you can:

Create a new stereo audio project. Place a stereo music track on track one. Open the Loudness meter and use at default EBU R128 and set the level of your track so that the Integrated LU meter peaks just below 0

Now, under file/properties/audio tab, change the audio properties to 5:1 and playback that same audio file and you will notice that the Loudness Meter is peaking at approximate plus 5.

If you open the surround panner for that track, at the bottom by right clicking, you have options to change the balance to -3db center, -6db center, constant power, film ect. None of those options actually get the Integrated LU meter to equal what was originally set up in stereo, though "film" is close, as is -6 db.

I also noticed that if you simply change your file properties back to stereo, the Loudness Meters show different Integrated LU than when it was first setup as stereo.

I understand that Loudness meters 'look ahead' and gauge Loudness by looking at changes. It also sums tracks which is why I think 5:1 comes across as so much louder.

In short, I'm trying to take a feature that I did a stereo mix in Vegas for broadcast and create a 5:1 mix of it for European distribution. My plan is to take the music and SFX tracks and distribute them in full surround with an LFE track and have the dialogue tracks reside on the front and center speakers with music (essentially I want to preserve the stereo mix on the front and center, and send the music and SFX to the rear/LFE as well). I was hoping to route the tracks without having to go through the whole film and rebalance/remixing each individual piece but rather keep the dialogue/sfx/music balance with 'legal' Loudness Meter specs which I had I achieved in the stereo mix.

 

adis-a3097 wrote on 1/7/2020, 11:14 AM

Well, by turning your project to 5.1 those 2 stereo channels get duplicated and routed to surround and center channels (turn down surround and center channels, like this, and you'll end up peaking the same on EBU 128), that's why the level uplift!

By upmixing, I was thinking of this:

https://www.waves.com/plugins/um225-um226

or this:

https://www.waves.com/plugins/dts-neural-surround-upmix

It can't be done in Vegas, I use "other" DAW to do so. You only can use Vegas to do a remix, or mix it completely from ground up.

On monitor levels:

https://www.masteringthemix.com/blogs/learn/the-perfect-monitoring-levels-for-your-home-studio

https://www.gearslutz.com/board/so-much-gear-so-little-time/1079034-what-spl-do-you-mix.html

https://www.gearslutz.com/board/geekslutz-forum/820961-mixing-70db-why-80-85-standard.html

https://www.gearslutz.com/board/post-production-forum/1065488-why-mix-films-anything-but-85db.html

 

James Moore wrote on 1/8/2020, 11:29 AM

Thanks again Adis for your comment. I am not interested in simply taking a stereo file and upmixing it to 5:1 but rather creating a 5:1 mix from my original files.

My mixing to date has been primarily in stereo and for broadcast and the introduction of the ITU-R BS.1770-4 standards has been my guide for using the Loudness Meters - the combination of Voice, Music and SFX 'fill up' to the -23LU level. The studio monitor levels are relatively moot in this scenario - god knows what the viewer, downstream in the broadcast system will be hearing it on. Of course what you hear is important when mixing (i.e. checking the mix at low levels on small speakers is helpful in making sure the music and SFX come through in the final).

Those discussions you linked to, and others I found, through me for a loop there a bit with mixing at -85db (and then some guys go own about 7 and 6 and 5) but I get it - set the studio levels at -85db and judge by what you hear but that brings me to a pet peeve I have about a lot of mixing, particularly for film, but I hear a lot in series work as well. Basically I hate mixes where you have turn up the volume to hear the dialogue and then you come to a Music/Effects scene and it knocks you out of your chair (or bed in my case with the wife waking up next to me..) with the loudness of that passage. You crank down the volume (apologize to the wife) and then you can't hear the damn dialogue again. This may play well in a decent theater set up at -85db but for most listening situations it doesn't. Personally I don't think the volume of the music and effects make it more 'dramatic', it's just loud in comparison to the dialogue. It's the content of the music and effects not it's loudness that give it emotion.

Which brings me back to the loudness meters and 5:1. By bringing the rear feed down, as you suggested, simply gives me my stereo mix again so that doesn't really solve my issue. My issue is what level the final mix should be for the rendered 5:1 file. Obviously you don't want it too hot as it'll distort, and in the broadcast world I keep the heat down to the -23LU but should I do that in the 5:1 world as well. My instinct suggests yes and that will require I spend more time leveling for my 5:1 mix to bring it down to the -23LU because it sums in the surround to arrive at it's integrated level. On the other hand though, why not leave it as it 'naturally' occurs - i.e. stereo is fine on loudness meter but 5:1 shows it hot because it summing all the tracks but the individual tracks are not in and of themselves 'hot' they are equally saturated as the individual stereo channels, there are just 6 of them.

I'm now leaning to the latter - the individual channels are nicely saturated, the same as individual stereo channels, there are just 6 of them...

Turd wrote on 1/8/2020, 12:11 PM

Thanks again Adis for your comment. I am not interested in simply taking a stereo file and upmixing it to 5:1 but rather creating a 5:1 mix from my original files.

My mixing to date has been primarily in stereo and for broadcast and the introduction of the ITU-R BS.1770-4 standards has been my guide for using the Loudness Meters - the combination of Voice, Music and SFX 'fill up' to the -23LU level. The studio monitor levels are relatively moot in this scenario - god knows what the viewer, downstream in the broadcast system will be hearing it on. Of course what you hear is important when mixing (i.e. checking the mix at low levels on small speakers is helpful in making sure the music and SFX come through in the final).

Those discussions you linked to, and others I found, through me for a loop there a bit with mixing at -85db (and then some guys go own about 7 and 6 and 5) but I get it - set the studio levels at -85db and judge by what you hear but that brings me to a pet peeve I have about a lot of mixing, particularly for film, but I hear a lot in series work as well. Basically I hate mixes where you have turn up the volume to hear the dialogue and then you come to a Music/Effects scene and it knocks you out of your chair (or bed in my case with the wife waking up next to me..) with the loudness of that passage. You crank down the volume (apologize to the wife) and then you can't hear the damn dialogue again. This may play well in a decent theater set up at -85db but for most listening situations it doesn't. Personally I don't think the volume of the music and effects make it more 'dramatic', it's just loud in comparison to the dialogue. It's the content of the music and effects not it's loudness that give it emotion.

Which brings me back to the loudness meters and 5:1. By bringing the rear feed down, as you suggested, simply gives me my stereo mix again so that doesn't really solve my issue. My issue is what level the final mix should be for the rendered 5:1 file. Obviously you don't want it too hot as it'll distort, and in the broadcast world I keep the heat down to the -23LU but should I do that in the 5:1 world as well. My instinct suggests yes and that will require I spend more time leveling for my 5:1 mix to bring it down to the -23LU because it sums in the surround to arrive at it's integrated level. On the other hand though, why not leave it as it 'naturally' occurs - i.e. stereo is fine on loudness meter but 5:1 shows it hot because it summing all the tracks but the individual tracks are not in and of themselves 'hot' they are equally saturated as the individual stereo channels, there are just 6 of them.

I'm now leaning to the latter - the individual channels are nicely saturated, the same as individual stereo channels, there are just 6 of them...

Hello James,

If I may, I'm specifically addressing your pet peeve about dialogue vs. effects audio levels.

This is only my opinion, so please don't think I'm quoting facts!

Completely opposite of your thinking, I like when audio mixes mimic real life as closely possible with today's production equipment. Isn't that usually the ultimate goal for producers -- to make the experience as "real" as possible? In real life, an explosion is quite a bit louder than two people having a conversation (the exception, of course, being when my beautiful wife is mad at me -- she gets pretty damned loud : ). I've spent a decent amount of money on my home living room system to make my TV/movie watching experience as real as possible and I'd be upset if a producer didn't take advantage of the $$$ and effort I put into my system.

I think most TVs and sound systems today include some sort of dynamic range compression control to compensate for your bedroom scenario.

Note to self (everyone else please look away -- the note that follows is a reminder for mine eyes only): Figure out a clever, kick-booty signature that suggests I'm completely aware of how to properly and exhaustively party on and that I, in fact, engage in said act on a frequent and spontaneous basis.

James Moore wrote on 1/8/2020, 12:17 PM

While I grant there are different views than mine, and I appreciate their expression - I don't want to suffer hearing loss due the reality of an explosion in a movie :) I am all for hearing, and feeling it's rumble though...

James Moore wrote on 1/8/2020, 2:09 PM

That Gearslutz forum is great. I found this thread which was really good. As I was reading it I noted what came up a few pages later:

"In the 2 years since I made that last posting, the CALM act became law and you no longer have a choice with respect to broadcast levels. No such restriction on film sound. Eelco Grimm has measured sound levels in a number of movie theater venues and has duly noted the considerable variations in dynamic range"

What got me going on this in the first place was the 'no choice' part I work with in Broadcast and wondering if there was an equivalent for film.

Great Thread - a bunch of pros:

https://www.gearslutz.com/board/post-production-forum/107770-film-amp-broadcast-levels.html