Dolby LM100 emulation?

[ricren]

Today I received a call from a client saying that he got a memo from Discovey Channel informing that from now on, they will enforce the use of the Dolby LM100 to measure the program loudness, specifying an average level for the complete program of -28 to -26 dbfs.
This "from now on" means that the program that we have to deliver in two days must comply with this tight spec.

i wonder if we can somehow "get close" to the readings of this device thru a combination of a few plug ins inside ProTools, like using an RMS meter adjusted to 300 ms. with an "A" weighting curve and reading only the dialog stem.
We currently use Spectrafoo for the RMS readings running in a separate machine.

This would be for this emergency situation. To grab a true LM100 will take us a week or more.
Any comments?

Ric

[TVPostSound]

I rented the LM100 lat week for the same Discovery requirement.

Plugins cant tell you the average of the whole program.

What I can tell you while palying back my program through the LM100 which passed me
at -27 dialnorm, I was watching my Analog Dorrough 280C meters. Kay Dorrough tells me its a 600ms VU response.
My average dialog VU (talking heads, and narrator) varied between -5 to -2.
My combined average VU when there was music under it read -2 to 0.
The peaks were limited to -12 during louder passages.

This is based on a calibrated 192HD analog outputs -20dBFS=0VU

I only passed after lowering the whole program by 2 dBs from my average mix.
The first pass was -29

Hope this helps

[ricren]

Tks a lot. This information helps a lot.
If you don't mind, I have a couple a questions:

1-You say "Kay Dorrough tells me its a 600ms VU response".
Which one has the 600 ms response? The LM600 or the Dorrough?

2-Asuming your 280C has the 0 db adjusted at -20 dbfs, your dialog averages -25 to -22 dbfs for a -27 reading at the LM100, right?

3-you say:
"I only passed after lowering the whole program by 2 dBs from my average mix. The first pass was -29 "

I fail to understand this statement. If you target is -27 and your first pass gave you -29, apparently you'd need to increase the level, not to lower it.May be I'm missing something.

cheers
tks. again for this valuable info.

Ric

[TVPostSound]

My Dorrough 280C has the 600ms response

The LM100 does not show instantaneous response. Its either 10 second average or infinite average.
There is a submenu where you could see instantaneous, but to me that part of the LM100 doesnt feel like a meter
and its hard to see in your peripheral vision while looking at 2 computer monitors, and a video monitor!!!

You have to run the whole show through the LM100 in infinite to get a final average (for Discovery).
The reading you would see is cummulative as you go.
Theoretically you can make the first half hour 3dBs hot and the second hour 3dBs low, and get the same average.

So, I played the 1 hour program once, and saw a -25 average, then lowered my master fader by 2dBs, and ran it
again!!!


I meant -25 sorry!!!




Dolby has the manual on line.

Asuming your 280C has the 0 db adjusted at -20 dbfs, your dialog averages -25 to -22 dbfs for a -27 reading at the LM100, right?

That would be the case since the Dorrough has a faster response time!!

[ricren]

Tks again. Very helpful.

Theoretically you can make the first half hour 3dBs hot and the second hour 3dBs low, and get the same average.

True, and that is just incredible. Or even you can make the first half 6 db hot and the other half 6 db low and get the same result. Unless the algoritm has some "intelligence " to detect "eveness" (is that a word?) thru time.
If there's not such an algoritm, I think this procedure is flawed because it says nothing about what the audience will percieve as loudness scene by scene.

cheers

Ric

[Richard Fairbanks]

I find Discovery's new needs laughable! They still use so much dynamics processing during broadcast that it does not matter what you send them! Maybe they are reconsidering this practice, but I doubt it because they still have all of their existing materials to recycle.

I think that suggesting LeQ measurements are flawed or useless is a little harsh. You can UP the level at one place and DOWN another to control the overall measurement, but of course you will not do this unless it is appropriate and sounds good. I think LeQ is a pretty good effort to control crazy "mastering" excesses (everything as loud as possible because that's what everyone else does) without enforcing abusive rules that can only flatten a mix further. Is there a better way?

[ricren]

I think that suggesting LeQ measurements are flawed or useless is a little harsh.

I did not say that. Let me explain my point:
I said that looking at just ONE global reading for the entire episode is not usefull. Because, as DiaFXMX pointed out, you can be way up in one place and low on another and the LM100 measurement will still say it's ok.

you say: "You can UP the level at one place and DOWN another to control the overall measurement,
but of course you will not do this unless it is appropriate and sounds good...."

In theory that is what it will happen following apropiate mixing techniques. But this is not what we've seen, so far.
Down here. we receive a ton of episodes for remix and M&E work and we noticed that many of them exibit segments with very different overall loudness.For example: In a 5 segment episode, the 4 and 5 segment could be louder than the rest. To the point that they appear to have been mixed by different persons or under different conditions.

Is that right? No. Does It happens? Yes, a lot. The Quality control detects that? Apparently not, because they go to air as they are.
What can I say? From my point of view one LM100 measurent for the complete show do not seem to be the solution.

Having said that,I really think LeQ based measurements are a good addition and a step in the right direction. But they need to implement it right! If not, It will be just another ADMINISTRATIVE step in our chain of work, and nothing meaningful for the audience.

Besides, I'm also feed up with this insane race for max-and out of control-loudness.

cheers

Ric

[CD Productions]

I too am mixing a show for Discovery. We ignored the request, and just continued using the Durroughs and Waves PAZ meter. So far nothing kicked backfrom QC. Whenever I see requirements like these I tend to assume its a broadcast tech with "some"knowledge of sound, who heard about somthing, and made it a spec.
I know over at the C.A.S. forum there was a long thread on LeQ and whether sound mixers should push for some kind of loudness standard for film mixes. Maybe not a bad idea. I know mixers who turn the stage level up to 90 db to please the action film producers. They have to mix with custom earplugs.

[Richard Fairbanks]

Okay, I understand. I'm sorry that I mistook your previous post! What you say about different segments being at different volumes, and the inability of one LEQ reading to point out the problem, is something I did not think about.

Some months ago I went to a screening of a documentary feature film, locally produced with grand eintentions. The film itself was good, but we were distracted over and over by the mix. As I said it was a documentary, driven by a narrator, and the mix raised and lowered the narrator. Every time the music blasted in for a montage, the voice over was raised up over it, all rather loud, then when the montage was over the VO level would fall back down with the rest of the dialog. With the next big montage music the same thing happened. I'm a sound guy so I'm sure I was more sensitive than the audience around me, but I stopped watching the film and began getting mad at the mixers. I like dynamics, but this was all handled in an inappropriate and inept way. And an LEQ meter would not have cared.

[TVPostSound]

Did you read the letter that came with the requirements from Discovery?
The idea didnt come from some broadcast tech!!!
This is Discovery Communicatons making a true effort to keep levels between programs EQUAL.

Im all for it.