How Much Headroom Do I Actually Have In The Box?

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(This article is not discussing how audio levels impact plugins, or what happens at an output leading to a d/a converter. This article is discussing the linear behavior of audio passing between channels within our DAW.)

What you’re seeing in the picture:

Going Up

  • Taking a test tone, calibrated to -18dbfs
  • Boosting that test tone to +762db of gain above zero (a bunch of gain plugins were used, each set to boost +30db each)

Coming Back Down

  • Routing the test tone through a second channel
  • Turning the signal down by -762db using the same number of gain plugins, bringing the signal back to the original -18dbfs.

I have MMultiAnalyzer on the master track, and I’ve set the resolution to -118.52db. That’s right down by the noise floor, and below it for many of you using lower end converters.

MMultiAnalyzer shows no added harmonics, despite the clipping lights going off on the channel in REAPER. This means nothing has changed in the original signal. It’s still a test tone, and will null against itself. When listening, the signal sounds identical to the original test tone.

Why +762db?

When I went above +770, the signal actually died and no longer produced a sound. When I removed the gain plugin that sent it over that +770db limit, there was still sound at +762db. So I left it there. The point was quite obvious at that point.

The Point

There is a limit to how much you can push a signal inside of your DAW. But that limit is so high as to be inconsequential to any of our mixing needs. Ignoring non-linear plugins, plugins with built in thresholds, etc…if we are talking about the linearity of the audio passing through our DAW mixer and what happens when you go over 0dbfs on your individual channels, you’ve got more headroom than you’ll ever need inside of the box. As long as you don’t clip the signal at a conversion point from digital to analog, you’re not actually clipping and are free to ignore the clipping lights on your DAW mixer if you so choose. I ignore them entirely, unless it’s on a channel feeding a converter. That’s really the only place I’m worried about clipping in the box.

TLDR:

In practice, you have infinite headroom. Technically, there’s a limit, but it’s so high that you certainly don’t have to worry about it during mixing.