A quick question of FCPX altering audio on export

Dear colleagues,

This may be an easy one, but one I have not found info on.
I have exported my feature movie timeline into a proresHQ file.
Then I noticed that, somehow, fcpx had automatically applied a limiter to the entire audio, crushing all sounds above 0db in a very cruel fashion.
Could anyone tell me please why this happens, and what I might do to avoid this happening to the audio?
Thanks.
Ivan

In digital audio zero is an absolutely limit. There is nothing beyond zero. Everything that is beyond zero is distortion, usually at a lower level, which makes heavily distorted audio actually sen less loud. It does not behave like analog audio that allows a larger range beyond zero before the audio reaches distortion.

mmm yes thanks for the reply but...
I can assure you that values of more than 0 DO exist, since I have edited them over months, and have them in front of me now. And as I now listen they not distorted.
I was intending to lower the sound myself to standard levels in any case.
What fcpx has done is crush all the sound spikes with a limiter, crushing all the levels from the original edit, down to the same level (and making 'jump scare' moments impossible with the sound).

Is there any way of avoiding this general 'crushing' of levels, without having to go back and lower by a few db each sound file in the edit (about 3500 of them)?
or a 'batch' way of altering all levels in the original edit?

thanks

I think I did answer the question. Zero is an absolute in digital audio. FCP displays audio over zero as an indicator how much it needs to be lowered. But whatever.

You appear to be answering your question with generic theory on sound.
And in that case, yes, as you say, whatever.

However if you did want to help or if someone knows: In the original timeline (that shows levels up to +6db), it offers you the opportunity (as you said) to lower the levels: that is, it still holds the info of the sounds above 0db (seen in variations between 0db and +6db).
Therefore values of above 0 do exist, or they would not be mentioned.
On export however, thee signals above 0db have been crushed on the same level, offering no possibility of correcting them.
I would be grateful to anyone who could offer a possible solution to lowering the general levels, that does not involve lower each sound file of this feature movie (about 3500 files).
Thanks

Let's first deal with the clipping above 0dB upon export.

This is done by any NLE, not only by FCPX, to avoid getting peaks above 0dB in the exported file. As Tom said: you simply cannot go beyond a certain point, and that point is 0 dB. This is inherent to any digital audio. Hard-clipped audio is not a good thing. That's why you have to make sure your audio never, ever goes beyond 0dB in your mix in the first place, so the audio won't have to be clipped when you export your edit.

Which brings us to your second question.

There are several ways for lowering the overall audio levels on an FCPX Timeline. If your mix is good but the overall output level is too high the easiest solution is to turn your entire timeline into a Compound Clip and lower the audio level of the CC.

Duplicate your project (for safety reasons), then press CMD+A to select all the clips on the timeline and press ALT+G to turn the selection into a Compound Clip.

Now you can just lower the volume of the CC until you get no peaks at all above 0dB anymore and export your CC. Or you can apply a Compressor to the CC if you know how to work with one, this will allow you tweak your overall audio even more. Most people never go any way near of 0dB in a digital mix. A peak output level at -6dB max with average audio ranging from -12dB to -6dB is very common.

- Ronny

Christ, yes, of course, making a compound clip of it all... That makes sense.
I was aware of the limits to the db levels (though I'll never understand why I am able to play straight from the edit in projections, with many levels above 0, without distortion), but thought that I'd continue to edit like that, based on the existing levels of the incidental music, then just lower the general level later on the export file.
But, by then, it had 'crushed' all sounds above 0 into a single level.
So, back to the original edit I go!
Thanks