How to measure headroom?

[c.roc.o.dile]

Hi, this seems like real basic information but I can't seem to find it:

The meters in DP go to +6. For example, the MW Limiter. When I'm measuring headroom, do I measure from +6 or from 0?

That is, if I want 6db of headroom, should the meter peak at 0 or at -6?

I've been recording and mixing for years but am brand new to mastering. Thanks in advance!

[daniel.sneed]

Not sure to see your concern, but inserting a Motu Trim (unity gain), after mastering stage, will tell you the truth about headroom.
Once you are sure about real headroom, you will take the Trim plug out of your master track, before printing master.

[HCMarkus]

Guessing this is the OP's concern: The "6dB" headroom "requirement" for mastering. But it is not really a thing. Any proficient mastering house can easily take your mix to any preferred level as part of the mastering process.

The REAL concern: DO NOT CLIP your mix track (unless you do so intentionally with a Clipper plugin, but you probably should leave that to your mastering engineer).

6dB headroom assures us the mix will not hit digital zero. It is a guidance, not a requirement.

PS: Please be sure you are using 24 or 32 bit audio file format in DP.

[c.roc.o.dile]

Thank you, Dan! The Trim plugin answers the question. You rock!

[labman]

As long as we are workin' in 32 bit float, and sending the 32bit float mix to mastering, there is no reason at all for us to go anywhere near '0'. Takes all the worry out of it. Easy peasy. (And most of the major mastering peeps MUCH prefer 32bit float for the deliverable to them.)

[EMRR]

A headroom mystery I have yet to answer regarding 32 bit float - had a bounce that showed clipping at roughly +3.5, turn the bounce file down below zero, yep, definitely clipped. The theory of 32 bit float says this shouldn’t happen. There were no mix bus plugs.