For those of you who tried the new Invert audio filter and were confused because you couldn’t see or hear any difference, here’s a video I found that explains what audio waveform polarity inversion is, and why and when it is used in audio mixing :
You might want to watch till the end. They show that in some cases invert polarity can be used to isolate parts of an audio file, like the vocals for example.
For the sake of dumb people like me who thought at first that this filter would make an audio clip play backwards, may I suggest to change it’s name to something more accurate, like “Invert polarity” maybe ?
Well seen. Lately I don’t have time to spend much time here. The name of the filter lends itself to confusions that can be avoided before they occur.
The word that would best describe the filter would be : phase inversion. As it is a 180º offset it is an inversion. http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html#tth_sEc2.60
In the case of a phase shift setting other than 180° it would be a phase shift filter.
Another example in Audacity.
A utility plugin that inverts the signal, also (wrongly) known as a 180 degree phase shift.
What I knew is that a wave (sine wave or other) with a repetition frequency, offsetting it by 180º becomes that same inverted signal.
In the case of an audio signal where there is no repetition of the same wave, then it is not appropriate to speak of a phase shift for a change in polarity.
So they are different concepts. I was wrong in my first comment.
