Audio Levels for DVCAM v. Beta

Hey guys,

I'm mastering a show to DVCAM and am having a few audio issues. My levels in FCP are all based on 0 db....from my tone to the last frame of my timeline. So...I send it out to my Producer and he says the levels are off the chart. He needs them to be recorded at -20 db. 9for Analog) on my deck. I have a Sony HVR-M15U and the only way to lower the levels on there is the -6 db. setting, it won't let me go lower.

Is there a setting in FCP for mastering to analog. I'm sure there are a lot of unclear holes in this story...please help me out on what I need to do. I have faith in you all.

By the way...I started a new account because my old one went kapoop! SO this isn'y my first rodeo here on the forum...I'm a longtime fan, just FYI.

-Jay B.

so you are comming out of fcp to the deck correct?

the deck has little level control.

1st

in fcp the audio levels should just dance at about -12 not 0. in audio 0 mean clip or distorted it the point that most audio becomes to loud to control in a digital format.

tone should be a study -12 for broadcast not dancing.

""" What you do with what you have, is more important than what you could do, with what you don't have."

> > > Knowledge + Action = Wisdom - J. Corbett 1992 """"

If you put the Bars and Tone signal on your show from the Effects tab, you'll find the tone level at -12. Play the bars and tone into the deck and adjust the input of the analog deck to Zero VU and the input of a broadcast digital deck to -20.

I gotta redo this so the file sizes is a little more usable, but wait it out. It tells you everything.

[www.kozco.com]

By the way, if your show levels constantly peak over about -4 to -6 or so, they may be too loud on top of everything else.

Koz

So...here's the issue, I'm mastering to DVCAM and sending it to my Producer. This is a digital deck, so should I assume that if I adjust the levels on the entire show after I've converted to a quicktime movie file, including bars and tone, I will be OK. He is mastering to Beta from there. What do I need to do on my end to get him a master he can work with?

I'm a little confused.

-J

Thanks by the way to you who have tried to help out....

You need to set your levels sanely for the digital domain, which is AT MOST -12dB average and more commonly -18 or -20dB.

0dB is the standard average level for analog audio ONLY. Ignore that, as you are not outputting analog audio - the recipient is. You are outputting digital audio, in which 0dB means you don't have a usable signal any more.

I'm positive the FCP manual has very good lay explanations of all this.

<<<I'm positive the FCP manual has very good lay explanations of all this.>>>

The web site has a video illustrating exactly where the tone and show levels should be for layoff to a DigiBeta machine. All broadcast digital decks use the same audio levels.

Your show levels should follow the illustration. If you mixed the show wrong, then just putting the tone in the right place will not help you.

If your particular deck does not have input level controls, then you are reduced to trimming the whole timeline to match. This is covered in the web site, too.

[www.kozco.com]

Koz

Just so we understand each other here, "Zero" VU and "Zero" on a digital peak reading meter are very different. An anlog VU meter is expected to occasionally go above zero. If you do that in digital, it will result in permanent damage.

Download and view the movies. They represent a short musical segment that is perfectly mixed for each meter.

We assume NTSC. The numbers are slightly different in PAL.

Koz

So Koz "The Guru of Sound",

Thanks for all of the examples...so, the show is cut and everything is kept to 0db. If I export as a quicktime movie can I then take all levels down to -12db. and make it work...or do I have to go into the timeline and re-mix everything making it peak at -12db?

This is so confusing to me for some reason. My producer is re-importing the master into his timeline and inserting commercials via DVCAM...so it seems to me, he can take care of this...true?

Thanks Koz...what do you think?

<<<everything is kept to 0db.>>>

What do you mean by that? We're talking about the bouncing balls on the Final Cut sound meter tool right? Zero on top and something like -80 on the bottom?

When you downloaded any of the three movies and rendered them to your timeline, ignoring the video for a second, did the Final Cut sound meter motion look like yours? Were your bouncing balls higher or lower on average?

That's one of the things these videos tell you. They all have perfect relationship between the tone (from Effects, Video Generators) and the show. If your bouncing balls are consistently much higher than my music, then they're too high. If they're much lower, then they're too low.

Also, note that if you have a dramatic show with lots of nighttime running around with guns, then you need to take that into account. But if you have the average reality/talk show, then my music and your balls should match.

After you straighten that out, then you can nest the whole show and drop it 8dB and lay it to tape. The tape meters should (as the web site explains) rest at -20 during the tone and around -12 to -14 for the show.

If your tape machine doesn't have good input level controls, then you must do it on the timeline before layoff.

Koz

Think of -12 dB in FCP as 0 dB. Using zero dB as the peak limit point is the way things were done in the analogue world. Unfortunately, a lot of the digital tricks are not as well known.

It is actually spelled out quite well in the FCP "Editing" Manual. It talks about how to set up your audio for broadcast and film and so on. It also does a good job of explaining in short order some of the differences between what is considered "hot" in various formats like DVCAM, Betacam and such. Also talks about the kind of dynamic range you want to have in your audio as well depending on where your final is being used. It specifically mentions the common occurance and setting the levels at zero in FCP and the broadcaster spitting it back saying it's too hot.

I still want to know what he was looking at when he mixed his work to "0 db." That could either be really bad or pretty good depending on what he was doing.

And yes, this is a black art. We had a company reject a tape because the tone wasn't at digital zero.

[sigh]

<<<Think of -12 dB in FCP as 0 dB.>>>

You want to be careful with that, too. The FCP meters are measuring electrical sound values. The older analog VU meter is measuring roughly loudness. I will post videos shortly illustrating how far off those two can be from each other on the same show.

Koz

It really depends on what/who you mix down for. I make sure that my final master is limited at 0, then i'll calibrate it to however loud whoever wants it. Bouncing between softwares, i peak around -6 to -12, never above 0, so I pretty much have around 12 dBs of dynamic range. 0dB is the absolute killer- nothing a fart higher than 0, or it clips. But why not -12? because volume levels are rendered horizontally by bits. At 0dBs, it's 100% bit usage, the softer the volume, the less bits used, resulting in lesser clarity (not that bad, but to preserve maximum signal integrity, I'll keep it as close to 0 until the final output. Basically, in the digital realm, you're safe as long as you never exceed 0. My guess is that -12 was intended as safety buffer in case some idiot actually distorts the signal, because it's irreparable after that.

>>Basically, in the digital realm, you're safe as long as you never exceed 0.<<

There's plenty of QC guys and gals who would debate that pretty fiercely. Digital 0 is a big no no for broadcast. Analogue is different.

"Digital realm" is a tricky definition, anyway. DV's reference level is -12dB, DigiBeta is -20dB, but that would be a bit low if you're burning your own video DVDs or audio CDs. All these formats are digital. Jude is right -- peak at 0dB when you're prepping a DigiBeta tape for broadcast and you're toast.


www.derekmok.com

soyi'

the levels coming out of fcp dv or hd, when set to -12db will not be acceptable when going to broadcast?

i go to dvd and the cable network converts it 4 me. there is a small charge however they mostly say its for audio reasons. would this level of -12db in fcp be the culprit?

what are the main reasons for the mix-down. other than levels and some eq tweaks i do nothing else. i have yet to ever use the audio mixer in fcp. however, i do use soundtrack. should i give more credence to the fcp mixer.

and whats this about bit rate during QT export?

""" What you do with what you have, is more important than what you could do, with what you don't have."

> > > Knowledge + Action = Wisdom - J. Corbett 1992 """"

Lol. You're usually not allowed to peak at 0 for broadcast. Stations usually have their own standards for submission- white, black levels AND audio levels. Some would want max peak levels at -12, some at -10. It Why do you not peak at 0? because anything a fart above it is toast. That includes +0.01dBs about 0. Digital, i mean the digital medium- a sampling rate, bits and measured on the decibel full scale. Transfer between digital mediums is lossless.

The standard for -12dBs 1khz is a new standard set by Apple and a few manufacturers. For digibeta, that standard was set at -20 years ago, some manufacturers set it at -18. Does it make a difference? "peak at -12, but don't peak at -0 else it distorts". In a recording studio, you'll record as close as possible to zero, but never above zero, same in mixdown and mastering. The rest are just calibration points. On the Avid- calibration point is by default at -20, on final cut, -12.

Bit rate results in a wider dynamic range, because you now have the bits that allow you to carry off the softer sounds (or louder, depending on which way you look at the charts)- 24 bit recordings (dvds and hd if i'm not wrong..), 16 bit for cd and dv. Sampling rate for dv, dvds is 48khz, cds 44.1. What to use, where to use, etc? Two basic rules is is the format you recorded it on, and what is the final output.