A question on dBs and headroom

[nate_dennis]

Originally Posted by Massive Mastering Article

dBFS: Deci-Bel (one tenth of a Bel) Full Scale -- On the digital recording scale, -0dBFS is the hottest signal you can have. "All ones." Top of the scale, can't get hotter, etc. Always "minus" as you can never go higher - So the reading will always be a specified amount below 0.

Line Level / 0dBVU: Just what it says. Line level. 0dBVU on an analog VU (volume unit) meter. Pro (+4dBu) or consumer (-10dBv) level, it's line level. We can also refer to this as RMS (Root Mean, Squared), or a level over a specific amount of time. You *can* go above or below 0dBVU. It's simply a nominal level to which basically everything audio is related to.

Headroom: The space between a nominal signal (in this case, line level) and the point where the circuit fails. In digital, basically anything under full scale (-0dBFS) would be considered headroom. In analog, it's the space between 0dBVU and the point where the circuit clips (failing completely). In analog, there can be a big difference between "headroom" and "USABLE headroom." We'll get into that in a bit.

Forgive my lack of technical terms . . . . but . . . .

On my 488mk2 the meter section has one for each channel, and a stereo master section. When the stereo master section hits 0 is that 0dBVU or 0dBFS? My goal is to create GOOD recordings, not necissarily LOUD recordings. I always hear "hit your tape hard" then some say "not if your running DBX." All of that considered . . . . to get the most out of deck, should i pushing past 0? I'm sure I should know all of this but, alas, I don't. Thank you for helping and not laughing in my face. (But feel free to laugh at me in your chair!! LOL) Thanks again.

[Farview]

If it is digital, it's dbFS, if it is analog, it's dbVU.

Another hint is that a VU meter has positive numbers and 0dbVU is somewhere around 2/3 of the way up the meter.

[nate_dennis]

yeah, it's definately analog. So I should aim to average 0dBVU? Thanks. I appreciate the response.

[Farview]

Yup. 0dbVU is the goal. That's what causes so much confusion in the digital world. 0db has been the target for 50 years in anaolg recording, then digital came along and put the target at some arbitrary point below 0, and then didn't tell anyone where...