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0 PPM on FCP Volume Meter (Dbfs)

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Emanuel Ach
0 PPM on FCP Volume Meter (Dbfs)
on Jul 13, 2011 at 4:49:38 pm

Hi,

I received some audio suggestions from our broadcaster and they said the peak should be up to 0 ppm.

1) There are so many kinds of ppm, so how much is 0 ppm on dbfs, is it -20 according to the American * guidelines and -18 in Europe. Basically I am interested in the Final Cut Volume meter, how much is 0 ppm there?

2) how much is 0 ppm to db also?

Thanks,


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Ty Ford
Re: 0 PPM on FCP Volume Meter (Dbfs)
on Jul 13, 2011 at 5:20:43 pm

Hello Emanuel and welcome to the Cow Audio Forum.

I usually post all my audio to -2 or -3 dB (below zero).

Here in the US, I'm told TV broadcasters expect peaks at -12 dB. Satellite slightly lower. Discovery has a very complicated formula for how loud and how soft an audio track can be. If they don't get it, they kick the project back for remixing. They are trying to make sure the audio levels are the same from one element to another.

In the end you need to know what the receiving party expects and give it to them.

Regards,

Ty Ford
Audio Forum Leader

Cow Audio Forum Leader
Want better production audio?: Ty Ford's Audio Bootcamp Field Guide


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Emanuel Ach
Re: 0 PPM on FCP Volume Meter (Dbfs)
on Jul 13, 2011 at 5:24:53 pm

I am told the peaks have to be under 0 ppm... how do I figure out this one with FCP 7?


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Ty Ford
Re: 0 PPM on FCP Volume Meter (Dbfs)
on Jul 13, 2011 at 7:07:25 pm

don't go over 0

Regards,

Ty Ford

Cow Audio Forum Leader
Want better production audio?: Ty Ford's Audio Bootcamp Field Guide


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Emanuel Ach
Re: 0 PPM on FCP Volume Meter (Dbfs)
on Jul 13, 2011 at 7:09:41 pm

0 dbfs you mean, Ty Ford, right?

Thanks,


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Ty Ford
Re: 0 PPM on FCP Volume Meter (Dbfs)
on Jul 13, 2011 at 7:31:23 pm

right.

anything above 0 dbfs is wrong.

Now where your destination wants the level (how far below 0 dbfs) is up to them

Regards,

Ty Ford

Cow Audio Forum Leader
Want better production audio?: Ty Ford's Audio Bootcamp Field Guide


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Emanuel Ach
Re: 0 PPM on FCP Volume Meter (Dbfs)
on Jul 13, 2011 at 8:04:04 pm

Thanks for all your help.

now DB goes all the way up to +12 right? and dbfs is only up to 0 right?

so that means that 0 dbfs is 0 db right?

Thanks,


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Richard Crowley
Re: 0 PPM on FCP Volume Meter (Dbfs)
on Jul 14, 2011 at 5:44:46 am

I'm not quite as confident as Mr. Ford. There appear to be several different PPM scales, and many of them do not even include "0" anywhere in the range. And those that do include "0", don't agree on what it means.

http://en.wikipedia.org/wiki/Peak_programme_meter#Table_of_characteristics

Without a definition of what "0 PPM" means TO THEM, I believe this "spec" is ambiguous at best, and quite possibly meaningless.

Who exactly is giving this "spec"? It that everything they offered? No reference? (Reference in both senses: Audio level reference; information reference such as a URL or spec document number, etc.)

What country are they in? Perhaps you could guess the reference from the country and/or broadcasting entity, etc. Do they possibly have a website with technical specs posted, etc?


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Ty Ford
Re: 0 PPM on FCP Volume Meter (Dbfs)
on Jul 14, 2011 at 10:27:19 am

Mr. Crowley,

with what do you take issue here?

"I usually post all my audio to -2 or -3 dB (below zero). Here in the US, I'm told TV broadcasters expect peaks at -12 dB. Satellite slightly lower. Discovery has a very complicated formula for how loud and how soft an audio track can be. If they don't get it, they kick the project back for remixing. They are trying to make sure the audio levels are the same from one element to another.

In the end you need to know what the receiving party expects and give it to them."


Regards,

Ty Ford

Cow Audio Forum Leader
Want better production audio?: Ty Ford's Audio Bootcamp Field Guide


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Ty Ford
Re: 0 PPM on FCP Volume Meter (Dbfs)
on Jul 14, 2011 at 3:38:45 pm

and here's another interesting site

http://www.sengpielaudio.com/calculator-db-volt.htm

Even so, it still comes down to what your client needs to see.

Regards,

Ty Ford

Cow Audio Forum Leader
Want better production audio?: Ty Ford's Audio Bootcamp Field Guide


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Eric Toline
Re: 0 PPM on FCP Volume Meter (Dbfs)
on Jul 14, 2011 at 3:51:01 pm

I think part of the problem is that there is no absolute standard of what meter readings mean. It's like temperature readings in farenheight or centergrade or speed in mph or kph We accept "0" as the digital maximum but how it's measured is the problem.

I think that using a voltage scale would be a better way. "0" is .775 volts ac, +4 is 1.23 volts ac. I'm sure that somewhere there is a volts to DB conversion table. The problem would be to get everyone to switch over to a simple universal standard.


Eric


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Richard Crowley
Re: 0 PPM on FCP Volume Meter (Dbfs)
on Jul 14, 2011 at 4:25:04 pm

@Ty, I apologize. I didn't mean to come off as disagreeing. I mis-read what you wrote. You are absolutely correct that "you need to know what the receiving party expects and give it to them." But it looks like Mr. Ach is having a hard time getting that information out of them. :-(


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Ty Ford
Re: 0 PPM on FCP Volume Meter (Dbfs)
on Jul 15, 2011 at 2:44:48 am

Richard,

No problem and I agree, they aren't asking for what they want well.

Regards,

Ty Ford
Forum Leader

Cow Audio Forum Leader
Want better production audio?: Ty Ford's Audio Bootcamp Field Guide


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Emanuel Ach
Re: 0 PPM on FCP Volume Meter (Dbfs)
on Jul 14, 2011 at 3:38:36 pm

Thanks to both of you for trying to help.

As a bit of an update, I asked them to tell me in DBFS however, they replied this:

"The peaks on DBFS should be up to 6 DB"

This seems crazy to me, if my peaks are around 0 dbfs, theoretically speaking, my peaks will be distorted. How can they say it's fine up to 6 DB?

Thanks,
Emanuel


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Richard Crowley
Re: 0 PPM on FCP Volume Meter (Dbfs)
on Jul 14, 2011 at 4:22:42 pm

It sounds like whomever you are communicating with doesn't know what they are talking about. Unless they said "-6dB" that little negative symbol is very important. Peaks at -6dB make perfect sense. There is no +6dBFS. It stops at 0dBFS, by definition.


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Eric Toline
Re: 0 PPM on FCP Volume Meter (Dbfs)
on Jul 14, 2011 at 4:33:47 pm

Your "0"db peaks are too high. As Richard noted, it's most likely -6 peaks that they are looking for. As a point of reference, normal broadcast standards in the U.S. are tone at -20 nothing hotter than
-10 all dbfs.


Eric


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Emanuel Ach
Re: 0 PPM on FCP Volume Meter (Dbfs)
on Jul 14, 2011 at 4:51:43 pm

Maybe they are talking about 0 dB analog. If that's the case I asked them what is 0 db analog on the dbfs scale for them.

From FCP Manual

There are several common digital levels used to correspond to 0 dB on an analog meter:

-12 dBFS: This level is often used for 16-bit audio such as DV audio, and for projects with compressed dynamic ranges, such as those for television or radio.
-18 or -20 dBFS: This level is more common on projects with higher dynamic range, such as professional post-production workflows using 20- or 24-bit audio.


I hope this will clear up my confusion.


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Emanuel Ach
Re: 0 PPM on FCP Volume Meter (Dbfs)
on Jul 14, 2011 at 5:25:44 pm

in final cut 7 when you go to "window" - "arrange" - "audio mixing" the volume meter goes there up to +12. that's a +12 above 0. Is that for dB?


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Richard Crowley
Re: 0 PPM on FCP Volume Meter (Dbfs)
on Jul 14, 2011 at 7:28:56 pm

That sounds like an attempt to make the scale look like the old analog days. In digital when all the bits are on ("Full Scale"), there simply is no more. You bang your head against the ceiling. ANY audio over 0dBFS is distorted and likely unusable.

As you observed, the transition from analog reckoning to the digital world is that "0dB" in the analog world is equated to some dB value of Full Scale (dBFS). Indeed, the professional standard is that 0dB analog is equivalent to -20dBFS digital. Or for prosumer or some applications like mastering for DVD, etc. 0dB analog may be set to be -12dBFS in the digital world. But NOTHING is above 0dBFS. That is why it is called "Full Scale". And the term dBFS implies "digital".


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Ty Ford
Re: 0 PPM on FCP Volume Meter (Dbfs)
on Jul 15, 2011 at 2:39:29 am

Emanuel,

well they are either old analog heads for whom + 6 dB is about as much as you'd want to go, or they are talking about -6dB on a 0 dbfs scale. Ask for clarification.

Regards,

Ty Ford

Cow Audio Forum Leader
Want better production audio?: Ty Ford's Audio Bootcamp Field Guide


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Andrew Rendell
Re: 0 PPM on FCP Volume Meter (Dbfs)
on Jul 21, 2011 at 8:34:25 pm

0 PPM makes no sense to me.

In Europe we use PPMs to measure our audio levels for broadcast (no other measure will do, which is a bit annoying as they can be quite expensive). Just in case anyone's looking in who doesn't know, a PPM is a meter with a very fast rise time, so that it follows the peaks, and a slow fall time, so that you can tell what the peak was after it's passed. It's not very helpful for judging apparent loudness but that's not what it's for (the holes in the sides of your head are the best things for that).

For the UK, line up level (our standard "zero" level) is a sine wave at -18dbfs and is displayed as 4 on the PPM scale. You MUST NOT exceed PPM 6, which is 8 dB above line up level.

Personally, I use this one: http://products.zplane.de/index.php?page=ppmulator


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Andrew Rendell
Re: 0 PPM on FCP Volume Meter (Dbfs)
on Jul 21, 2011 at 8:42:28 pm

By the way, the PPM scale is behind newbies taking delight in the witticism that the BBC's motto is "Nation Shall Peak Six Unto Nation" (like sex, every generation thinks that they invented it!). But then, very bad rhymes, puns and sarcasm have a long and revered history over here.


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