Envelope tool and preserving quality

[KlarkKentThe3rd]

I want to use Envelope, but without modifying the entire track.

It can still be done, but it gets more complicated.

1) Import the file
2) select the part that you want to apply the envelope tool to.
3) Duplicate that part onto a new track. (Ctrl+D)
4) Delete that part from the original track
5) Apply the envelope to the duplicate
6) Ensure that dither is enabled for high quality conversion.
7) With the duplicate track selected, "Tracks menu > Mix and Render"
8) From the track drop down menu, set the sample format to 16 bit (this will apply the necessary dither).
9) "Edit > Preferences > Quality: High quality conversion settings" set dither to none.
10) Select all of the silence in the duplicate track.
11) "Edit menu > Remove Audio or Labels > Silence audio" (Ctrl+L). This will remove unwanted dither from the silence.
12) Export to 16 bit WAV
13) Edit > Preferences > Quality: High quality conversion settings" set dither to "shaped".

but as I said, it's really not worth the effort other than as an academic exercise.

I had this feeling that this is how it's done. I will do that, but I wish future versions of Audacity will just have an improved fade-out option, making it truly adjustable (like Envelope).

[KlarkKentThe3rd]

And last question: would it be okay to apply dither to the entire track I want to fix the fade-out to? Would it be very noticeable?

[Robert J. H.]

You can use an external dither program to apply the dither only to the fade-out section.
Stay in 32 bit float, create the envelope, mix&Render to a new track, apply dithering (plug-in) and export this track.
The internal dithering has of course to be turned off.

[KlarkKentThe3rd]

You can use an external dither program to apply the dither only to the fade-out section.
Stay in 32 bit float, create the envelope, mix&Render to a new track, apply dithering (plug-in) and export this track.
The internal dithering has of course to be turned off.

I guess I will have to stick to dithering everything. Not too bad.

Problem solved, I guess?...

[steve]

would it be okay to apply dither to the entire track I want to fix the fade-out to?

Absolutely, but only apply dither once.
By default Audacity applies dither when exporting to 16 or 24 bit format, so you do not need to manually apply dither ever.

Would it be very noticeable?

Not noticeable at.
If you compare an "all dithered" to a "not dithered" export file, you may notice a very slight difference at the very tail end of the fade out. The effect of dither is only noticeable when the signal level is very very low, where dithered 16 bit audio has a tiny bit of hiss whereas not-dithered 16 bit audio is a tiny bit crackly and raspy. Elsewhere the effect is inaudible.

For 24 bit audio, many studios don't use dither at all because the effect is completely inaudible whether you use it or not (though it IS used when converting from 24 bit to 16 bit)

[KlarkKentThe3rd]

Thanks, everyone!

But... I have one more question. When I am using Envelope, I can lower the volume at the end to increase the fade-out. This is where the values of the bits are changed (I assume). However, the segment that I am not editing (97% of the track): does IT get affected?

This is what I am referring to:
http://i1324.photobucket.com/albums/u61 ... 1394154703

If I carefully drag the tool to the very top, or "one", does it mean the rest of the track will hopefully be unchanged by the Mix & Render command?

In other words, how can I be sure the rest of the track keeps its original volume?

Preemptive thanks.

[steve]

Where you drag the tool to the very top, ("one"), the track keeps its original volume.

[KlarkKentThe3rd]

Where you drag the tool to the very top, ("one"), the track keeps its original volume.

Thanks again. I feel uncomfortable asking so many questions, but I really know almost nothing, and this is the only place I can learn.

[Gale Andrews]

I wish future versions of Audacity will just have an improved fade-out option, making it truly adjustable (like Envelope).

Have you tried Effect > Adjustable Fade... (underneath the divider in the Effect Menu)?

Or do you mean that you want to set Fade Out or Fade In so that they run (without dialogue) using some pre-determined custom shape?


Gale