signal chain DBVU question

W

wang191

New member
I was reading on bluebear's website about the signal level between analogue and digital. This is not new news to me by any means but I started looking into it further. All the sites say that you need to push the analog gear up to get near 0db on digital meters. But if 0db on analogue gear has about 24db of headroom left (on good gear) and if you want to leave head room on your digital gear then wouldn't you want the 0db analogue to match about -24 on your digtal gear. All the sites say to push up the signal as close to 0db (digital) as possible, but that seems to leave no head room.

-24db is kinda low even for digital. I know i have read everyone saying -12db to -6db is a good place to keep the signal. So you woudln't want to push your analogue gear in the +4 or more just to match it to 0db on the digital gear. You want it to match at less.
I just find it odd that none of the places online come to this final conclusion.

Would this be correct thinking?
 
bare in mind, i'm no expert at this stuff and in fact have been researching more into level matching recently.
but yes, if you're going from digital to analog, you're going to need to drop you reference level down quite a bit.
In the music world "usually" audio stays in one place. Since the final medium for music is CDs....you don't really worry too much about the analog world in a typical home studio. Yes there is analog gear you might use to process, or you may bounce it to tape to get some saturation...and then is when you need to worry about level matching. In Post Production this is very important. Many times tapes are being bounced from analog to digital and back to analog. This is why there is a reference tone on tapes so that people can set levels accordingly. A typical standard in the post world is -20dBFS = 0VU (Europe is -18 I think). What this means is that the average level of your music should hit around -20dBFS and a lot of people suggest having peaks every once and awhile hit around -10 is okay. So there are standards in place, it's just not everyone follows them which you'll find a lot of engineers are getting annoyed about. Even analog tape has several different standards of which you can use!! Bob Katz has had several discussions about his proposal for setting a new standard. You can find some info at:
http://digido.com/portal/pmodule_id=11/pmdmode=fullscreen/pageadder_page_id=55#Levelling_questions
and there is also an AES Proposal I have sitting around at work that he wrote which I can try and find if you want.

Then there's also the discussion of the loudness war people are fighting, which makes it even worse. There are people trying to make the entire mix around -.02dBFS for the whole 5 minutes of the song.
But basically, yes there are standards in place that you should follow. Find out what medium you're going to and what the recommend (or requested by the client) level should be set at.

maybe someone else here can help expaint it better for you and correct anything I may have said. ;) :cool:
 
wang191 said:
I was reading on bluebear's website about the signal level between analogue and digital. This is not new news to me by any means but I started looking into it further. All the sites say that you need to push the analog gear up to get near 0db on digital meters. But if 0db on analogue gear has about 24db of headroom left (on good gear) and if you want to leave head room on your digital gear then wouldn't you want the 0db analogue to match about -24 on your digtal gear. All the sites say to push up the signal as close to 0db (digital) as possible, but that seems to leave no head room.

-24db is kinda low even for digital. I know i have read everyone saying -12db to -6db is a good place to keep the signal. So you woudln't want to push your analogue gear in the +4 or more just to match it to 0db on the digital gear. You want it to match at less.
I just find it odd that none of the places online come to this final conclusion.

Would this be correct thinking?
Click to expand...
Not really -- the last thing you want to do is push your analog gear so hot that you cut into IT'S headroom. With 24-bit digital recording, there's absolutely NO NEED to be getting the levels anywhere near 0dBFS (digital meters).... most digital gear set at the appropriate gain structure is calibrated to see an average analog signal somewhere around -15 to -12dBFS which is just fine - particularly as I mentioned, with 24-bit digital recording.

I'm not sure what sites you're going to that tell to get the level up to 0 dBFS, but that's a load of nonsense. It was even over-emphasized too much with 16-bit recordings, but now with high-quality 24-bit converters, it's a complete non-issue.
 
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