Wrong shape of Fade-Out in WL 12 Editor with very short fade time

So here is a weird one. Using WaveLab Pro 12.0.10, Windows 11 Pro 23H2.

When I recently edited some files in the Audio Editor of WaveLab 12, I noticed that short fade-outs (less than 100 ms) didn’t have the shape they should have.
I did some tests with a simple generated signal (Stereo, 44100 Hz, 32 bit float; 22049 Hz sine wave at 0dB) and found a threshold at which the shape of the fade gets wrong. Here some screenshots of the different wrong shapes:

The threshold is at exactly 8184 samples. If I expand the selection to be faded by just 1 more sample to 8185, the fade is applied correctly though, see the next screenshots:

The wrong shapes actually seem to be Amplitude Compensation Variations like the ones you can select for a clip in the Audio Montage (therefore “Linear” and “Sinusoid” do not show any differences), but as far as I’m aware there is no such option within the Editor - so how can this happen?.

I did some further tests with different amount of channels, sample rate and bit depth with the following conclusions:

  • This issue occurs only to Fade-Out and only in the Audio Editor.
  • It seems to be tied to the selected amount of samples. 16368 samples or less for 1 selected/faded channel - 8184 samples or less for 2 selected/faded channels - 2728 samples or less for 6 selected/faded channels, and so on (the threshold is basically 16368 samples divided by the amount of simultaneously selected/faded channels). Expanding the fade selection by just 1 sample above the threshold results in the correct fade shape in every case.
  • The sample rate or bit depth of the file doesn’t seem to matter.
  • The actual file lenght doesn’t seem to matter.
  • It doesn’t seem to matter, whether the selection/fade is done at the end of the file, at the beginning or anywhere within the file.
  • No such issue in WaveLab Pro 11.2.0.

Can anyone else confirm this? PG?

With a quick test, I confirm something similar to your finding. I will need to experiment further and then I come back to you.

Thanks PG.

Further on the topic of fades I noticed, that I can’t create a Fade-In nor a Fade-Out with less than 4 samples selected in the Audio Editor. It might be a rare case, but it still can be useful to smooth out some harsh sudden starts and ends of a file. It also was possible in WL 11.2 (and it is still possible in the Montage in WL 12) to fade with just 1 sample (well, maybe 2 samples for a Fade-Out to make sense).

This will be fixed in WaveLab 12.0.20.
Also, fades will be possible from 2 samples.

Thank you, PG!