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Setting Tone on Beta Deck
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We’re having a strange problem coming out of Final Cut Pro. We’re outputting a DVCProHD 720p 59.97 sequence using our Aja Kona LHe to downconvert to standard def. I’m outputting via component to our UVW-1800 Beta deck. The picture is fine but when I set our -12db FCP tones to 0 on our Beta deck all of the audio in our show comes out extremely low. This is very strange since the show is pre-mixed to that -12db tone. On the FCP meters all the audio is at or around -12 but on the beta deck it is barely registering even though tone reads 0. Our DVCam deck reads the audio levels fine. Our DVCam deck is fed by RCA and our Beta Deck is fed through XLR. We’ve tried hard patching straight from the Kona card to eliminate the possibility that our mixer is the problem. It still read our sequence audio very low. I worked around the problem by setting our 0 tone to -19 in the FCP sequence but am curious as to why I had to do this.
In summary… How can a sequence be mixed relative to a tone but still come out so low on our analog meters even though those are set to the same tone? Much thanks.
Quinn Costello
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6 Replies
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This is probably part of an age old and oft raised issue.
The answer is usually that the metering in FCP is different from that on your Beta deck.One test for you, is to output your Ref Tone & Program to tape, then batch both of them back in and see if there’s a difference between the Tone and Program.
If there isn’t, you can be assured it is a difference in metering between the two devices.
As i said, this issue has been covered often since the arrival of NLEs, but I can’t point you at any definitive discussion. Maybe someone else can help, there.
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Not sure why anyone uses -12 for tone when every tape I have come across from various vendors has tone at -20.
If you set fcp tone for -20 and set your betasp for zero (first red bar) thats how its done.
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Ref Tone at -20dB is for Digital and
Ref Tone at -12dB/-14dB is for Analog.Need to check exactly what the broadcast standards say.
Anyone got a link to them? -
[Borjis] “If you set fcp tone for -20 and set your betasp for zero (first red bar) thats how its done.”
Agreed, and Costello, get yourself an analog mixer to adjust as needed. If you set your bars for -20db and leave the rest of your timeline alone and adjust your Beta deck to the new reference tone, that should basically even out what you are seeing on your analog deck to the correct levels. The biggest difference between analog and digital audio is that, with analog audio everyone was always in a race to 0db and not to peak too much over that reference. With digital, many of your levels will be over reference (ie -20db) but an an analog scope, your levels will not peak. Confusing but true.
Jeremy
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Thanks all-
This seems to make sense. When I set my bars to -20 the levels seem fine on the Beta deck. What about mastering to my DVCam deck, though. When I set my bars to -12 on that deck everything looks fine. Should I use -12 as the level on that deck? Much thanks.
Quinn Costello
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Ironically tone is an irrelevent concept in digital transfers. It is only relevent in the analog domain.
Here are the rules for broadcast. Reference tone is -20 dbfs (Full Scale on a digital peak meter) in the NTSC world and PAL is -18dbfs. Program peak signal levels shall not exceed this reference level by more than 10db (again on a digital peak scale).ie Maximum peaks shall not exceed -10dbfs.
When dubbing to an analog machine with VU meters (basically all SP beta decks) set the -20dbfs tone to be 0 VU. On a digital dub (DVCAM, digi beta etc) use the digital signal either embedded or AES. Do not adjust your levels. Tone should show as -20 (or -18 for PAL). Digital machines all have digital peak meters that scale up to 0.
The fact that FCP tone default it -12dbfs is perplexing to me as the broadcast standards for reference tone have neen around for over a decade. If you follow the broadcast rules of -20dbfs with peaks no more than -10dbfs, you will always have correct levels.
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