Tone in FCP
by vjrook (VJROOK)
on
Jan 14, 2007 at 10:36:27 pm
Hello -
My boss has 10 years AVID editing experience, but no FCP experience. I have 2 years FCP editing experience. We are running FCP directly to the Sony DVCAM deck via firewire.
When I put bars and tone in my sequence, my boss tells me to lower the decibel from -12 (fcp default for tone) to -20. He says that FCP "has it all wrong, and that all bars and tone should be set at -20". This is the decibel level that tone plays out of the Avid, which runs the sound through a mixer before reaching the deck.
Most of our projects are non-broadcast (though we've done some spots), but I would like to know for my own edification, what is the deal here? How should I use bars and tone for my shows.
Re: Tone in FCP by Rich Rubasch on Jan 15, 2007 at 4:21:56 am
If a station receives a tape at -12 don't they set it up to their level? As long as the audio isn't clipping. In both my DVCAM and Beta decks the output directly out of FCP at -12 matches perfectly the preset input level on both decks. If I set FCP tone to -20 then I'm certain the record level presets on the Beta would be way low.
Also, audio discs we get from both audio houses here seem to line up exaclty with -12 in FCP.
Hmmmm, curious about this one... -12 would be my guess.
Re: Tone in FCP by rafalaos on Jan 15, 2007 at 6:01:26 am
If your film will be played through a theater like audio system , -20db will be great, but if is to be played in TV or computers -12dbs is perfect. -20dbs doesn't mean that we are recording the audio very low, but that the difference between the average level and the peaks is very hight To reproduce all this range you need a good sound system. When you broadcast audio with 20dbs dinamic range, this must to be compressed on broadcasting.Normal TV sets can not reproduce sucha wide range. If you set it to a normal level you will loose the most subtle sounds, and if you set the volume to listen these subtle sound the peaks will break and distort.
When you set bars and tone in a Betacam tape you set it a 0dbs, but Betacam use analogic audio and this level is related with the signal you can record in a magnetic tape without saturate the tape. In analogic you can overstep the 0db , in digital when you arrive to 0dbs you got nothing.
To put some bars and tone in the beguining of the movie is a good policy because will give the best refference to any posterior adjutment, both audio and video.
salud,
rafael
Re: Tone in FCP by walter biscardi on Jan 15, 2007 at 11:15:47 am
[Rich Rubasch]"Hmmmm, curious about this one... -12 would be my guess."
If you deliver -12 tone to a broadcast network they will reject it and send the tape back to you. We deliver to both US and European networks right now and all have -20 as their spec. that's an easy thing to fail in Quality Control.
Walter Biscardi, Jr.
http://www.biscardicreative.com
HD Editorial & Animation for Food Network's "Good Eats"
HD Editorial for "Assignment Earth"
"I reject your reality and substitute my own!" - Adam Savage, Mythbusters
Re: Tone in FCP by Oliver Peters on Jan 15, 2007 at 1:12:59 pm
By and large broadcasters are using SDI throughout their plants. They are geared to seeing tone on digital decks (Digital Betacam, DVCAM, DVCPRO, etc.) at a unity level, which is -20db. Yes, they can adjust it lower, but -20 is the norm.
Sincerely,
Oliver
Oliver Peters
Post-Production & Interactive Media
Orlando, FL
www.oliverpeters.com
Re: Tone in FCP by walter biscardi on Jan 15, 2007 at 1:21:23 pm
[Oliver Peters]"Yes, they can adjust it lower, but -20 is the norm."
Yes they CAN, but in our experience they won't. It falls on the Post House to deliver proper spec masters and if tone it out, that will fail quality control from our experience.
When we first started testing our HD workflow, that was the first red flag on our first test master sent to quality control. "Tone is too high, -12db, and must be re-set to -20db" Easy fix on our end and since then, all of our broadcast masters are set to -12db digital.
Walter Biscardi, Jr.
http://www.biscardicreative.com
HD Editorial & Animation for Food Network's "Good Eats"
HD Editorial for "Assignment Earth"
"I reject your reality and substitute my own!" - Adam Savage, Mythbusters
Re: Tone in FCP by Chris Poisson on Jan 15, 2007 at 2:31:43 pm
What I was told a long time ago by several post houses here is that -12 is for analog masters and -20 for digital. Since all my tapes for TV have gone out on Beta SP at -12 over the last 6 years to stations in all the Western states, not one has been kicked back.
Re: Tone in FCP by Oliver Peters on Jan 15, 2007 at 3:18:38 pm
[Chris Poisson]"I was told a long time ago by several post houses here is that -12 is for analog masters and -20 for digital"
Chris,
This is incorrect. -12 came about because this was one of a number of level settings that have been acceptable with digital devices. The bottom line is that it doesn't matter, as long as your audio mix matches a range valid for the reference tone provided. If you are working against a reference of -12, you theoretically have 12dB of headroom before clipping. If you work against -20, then you have 20 db. In reality, for video as opposed to pop records, you would never want to go all the way up to digital 0 with peaks in a mix. You want to stay within about 6 to 10 db over your reference for going to digital tapes. So, if you set your tone to -20 and your mix averages around -12 to -10 on peaks, you'll generally be OK when going to a Digibeta.
Unfortunately, this isn't correct when you go to Beta-SP. Here you have a different type of meter (different ballistics on peaks) as well as less headroom. The general rule here is to set your FCP tone to -20 and then set your Beta-SP record levels to 0 VU with the deck's limiter turned OFF. Then adjust your mix so that the peaks run no higher than +3 (as measured on the deck's meter). Now turn ON the deck's limiter. This should give you a pretty good mix onto Beta-SP.
The one caveat to this discussion is that a number of broadcasters and networks are adopting the Dolby Dialnorm values for mixes. That pretty much invalidates all of this common wisdom and requires that you either purchase the expensive Dolby monitoring or go with an audio post house that properly understands how to deliver a mix according to these specs - with or without the Dolby gear.
Sincerely,
Oliver
Oliver Peters
Post-Production & Interactive Media
Orlando, FL
www.oliverpeters.com
Re: Tone in FCP by walter biscardi on Jan 15, 2007 at 3:23:13 pm
[Oliver Peters]"Unfortunately, this isn't correct when you go to Beta-SP. Here you have a different type of meter (different ballistics on peaks) as well as less headroom. The general rule here is to set your FCP tone to -20 and then set your Beta-SP record levels to 0 VU with the deck's limiter turned OFF. Then adjust your mix so that the peaks run no higher than +3 (as measured on the deck's meter). Now turn ON the deck's limiter. This should give you a pretty good mix onto Beta-SP."
yep, that's what we find here, good point.
Walter Biscardi, Jr.
http://www.biscardicreative.com
HD Editorial & Animation for Food Network's "Good Eats"
HD Editorial for "Assignment Earth"
"I reject your reality and substitute my own!" - Adam Savage, Mythbusters
Re: Tone in FCP by Peter Wiggins on Jan 15, 2007 at 3:24:42 pm
My 5 pence worth here in the UK, set everything to -18db for digibetas as most machines have been modified.
Peter
Re: Tone in FCP by walter biscardi on Jan 15, 2007 at 3:27:59 pm
[Peter Wiggins]"My 5 pence worth here in the UK, set everything to -18db for digibetas as most machines have been modified."
well, you guys DO have to be different over there after all. -12 and -20 were already taken, so make it -18 just to screw with us on "the other side of the pond." :-)
Walter Biscardi, Jr.
http://www.biscardicreative.com
HD Editorial & Animation for Food Network's "Good Eats"
HD Editorial for "Assignment Earth"
"I reject your reality and substitute my own!" - Adam Savage, Mythbusters
For what it's worth, Mr Biscardi is correct..I've worked at both HBO and Discovery (my best friend actually was a QC tech at HBO as well)...never heard of anything but -20 for broadcast.
Re: Tone in FCP by walter biscardi on Jan 15, 2007 at 5:34:23 pm
[Proper Modulation]"Mr Biscardi is correct."
First of all, it's Walter, and there's a bunch of us on here who have said -20db so it's not just me being "correct." Except of course for Peter who has pointed out that in europe he delivers -20.
But that is strange because we're delivering a show overseas right now and they want -20db.
Walter Biscardi, Jr.
http://www.biscardicreative.com
HD Editorial & Animation for Food Network's "Good Eats"
HD Editorial for "Assignment Earth"
"I reject your reality and substitute my own!" - Adam Savage, Mythbusters
Re: Tone in FCP by JeremyG on Jan 15, 2007 at 4:06:42 pm
Cool, and on the front of that deck there should be some audio meters that have a little triangle as to indicate where tone should be. Where are they? -20?
Re: Tone in FCP by Vince Sanchez on Jan 15, 2007 at 6:42:23 pm
For the shows we've delivered its always -20dbFS for digibeta and 0db VU for analog (Beta SP) for the tones. Program level not to exceed -10dbFS on the digibeta. To do this we mix audio to hover around -20 and set the peak limiter to brick wall at -10dbFS. This seems to work really well when dubbing to Beta SP, gives us a full level without overmodulating the SP deck.
Re: Tone in FCP by Seamus on Jan 16, 2007 at 1:37:22 am
I remember working in the UK a few years ago (now back home down under). Digi decks I worked with all set to -18db.
but in the end, in theory it doesn't matter does it? If it clearly says at the beginning of the tape what the tone is set at. Then thats all that is needed. Its just a reference point so all users of the tape are on the same page. is it not?
so is it just a matter of stations standardizing the process so there is no possible glitches or mistakes on settings?
Audio has always confused me for the same reason its a long thread here. Different standards. I don't do final mixes for broadcast for that reason, I send it to a audio house.
Re: Tone in FCP by rafalaos on Jan 16, 2007 at 8:43:56 am
In the end nobody had explained jet how to use the tone. First the tone has to be a reference for your self when editing. When somebody tells you that wants the audio at -12 or -20 or whatever the important matter is not the levels of the bars but the audio average level. If you work (i.e) -12db, set few seconds of bars and tone (-12db) in your time-line a play it. You will see in the FC audiometer that the green horizontal bars stay at -12db. Set the volume of your loudspeaker so the tone is clear and hight enough but do not disturb you. Now DO NOT TOUCH THE VOLUME OF YOUR LOUDSPEAKER ANY MORE because this will be your reference for the whole editing. And now you have to start to lie your audio down setting the levels so the mix your are getting through your loudspeakers its sound OK to you. If you set a dialogue for example the green bar of the audiometer should be around those -12db. The other thing you must to look at is the small horizontal yellow bar in the audiometer. That mark de peaks and you shouldn't let it rise much on top of the -6 dbs. If they ask you to work at -20dbs, just do the same but adjusting the audio at with a tone at -20db and your average audio level around this.
As I tell you the tone has to be a reference firstly for your self. If you set few second of tone in the beginning of your film this will help to adjust the optimal level when reproducing the film What I do is to ask my customers which audio level they want. If they don't know, i go to -12db. I have never had any complain and the truth is that I have been requested to set -20dbs in a documentary that was going to a film festival and was to be shown in a big screen. About specs you will find people very strict and people that don't give a damn.
Somebody mentioned Beta-cam. When we are recording digital or anagogic signals, we are in two absolutely different worlds. When you digitalize the same audio with to different levels, you are getting two completely different files (two different strings of "0's" and "1's" that you get in your tape or in your hard drive). When you are recording in anagogic and you are rising the AUDIO REC level the only thing you are doing is giving more strength to the magnetic field you are creating in your audio heads. In anagogic is very important that the metal particles of the video-tape get magnetized to the higher possible level but without over modulate. This is what you get in a Beta-cam when you record a tone at 0dbs, the optimal magnetic flux, the higher signal to noise ratio. When you play the tape, the reproduction will be optimal. If you had record to low you can increase the volume when playing, but you will rise the noise too. if you record too hight, then you risk interferences in-between the adjacent audio-tracks or even with the video-tracks, also problems of print-through in the tape. A similar process of the Audio is done to the video signal when adjusted through a TBC with.
In digital tapes the strength of the magnetic signal that you lie in the tape is not that important. You are writing "0's" and "1's" and as long as the video heads can tell between a "0" and a "1" you will recover the full information without any loose.
Salud,
Rafael
