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0 PPM on FCP Volume Meter (Dbfs)
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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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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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@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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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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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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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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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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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 -
Richard,
No problem and I agree, they aren’t asking for what they want well.
Regards,
Ty Ford
Forum LeaderCow Audio Forum Leader
Want better production audio?: Ty Ford’s Audio Bootcamp Field Guide -
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: https://products.zplane.de/index.php?page=ppmulator
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