Maybe OT

[Steve L]

Audio 'instructions' for a file I am to process. Levels should be plus and minus 6db at -18 db. OK so no higher than -12 db and no lower than -24 db. But when I process the file (Levelizer) it seems to be very low. I am confused about the actual meter labels. Is 0 zero? I remember -12 is 0 on DAT units years ago. Oh well just throwing it out for somebody to explain it to me.!

[Ian Alexander]

I think zero is zero, the top of the digital scale, 0dBFS. But on the Sonoris meter, for example, zero is a moving target. Depending on which scale I choose, zero is -12, -14, or -20. I ignore this user-chosen silliness and stick with zero is zero.

As for the level after processing with a compressor or limiter, you just need some makeup gain. On the Levelizer, makeup gain or output level is right below the blue triangle on the right. Use the comp/lim to get the dynamic range you need. With a range of 12 dB, I don't know how much limiting you need, btw. Then use the makeup gain to center the level at -18.

If you have the levelizer patched prefader, you can also use the MT fader to get the level centered at -18. If the initial levels were really low, you may have to use both.

HTH.

[Bill Park]

I remember -12 is 0 on DAT units years ago. Oh well just throwing it out for somebody to explain it to me.!

That would not be correct. Depending upon which DAT you reference, 0= -18 or -20.

[Cary B. Cornett]

This "zero confusion" is why we use more than just the number.

"0 dBfs" means "zero decibels below full scale". Inside any digital system, it is the most convenient, because the number tells you "how far below SPLAT!".

"0 VU" is not as well-defined relative to the actual signal. It comes from when the old mechanical "Volume Unit" meter was the industry standard, and all experienced engineers knew how to use it to help them set levels. For the meter itself, it represents a certain voltage, but in actual use, it is a completely arbitrary standard, depending on what the system designer wanted. When the film sound guys went digital, they agreed on a standard that said
"0 VU = -20 dBfs".

When you are trying to give a client something with a consistent "loudness", it gets tricky. The straight-up peak meters used in SAW don't tell you how loud it SOUNDS. For seeing how "loud" my mixes are, I like to use the K-metering system developed by Bob Katz. It shows me both peak and average levels at a glance, and I find that matching average levels between mixes works pretty well. The Sonoris meters have this option.

HTH