Phase rotation, is there a plugin for mastering?

Getting Stuff Done How do I .... ?
#1

I recently saw this video and tbh never thought about phase rotation in that way

is there a plugin in linux that does the same thing as shown in the video?

thanks!

#2

or asked another way: is this really an issue ? or can i fix this, especially with vocal recording, by removing dc offset on the single tracks beforehand? not sure if i understand the whole concept though…

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#3

Not surprising, the semi-explanation in the video is more confusing than correct.
The description on the iZotope page I think is more understandable, although it helps to have some familiarity with Orban radio processors:
iZotope phase rotation tool page
See this Orban paper:
Orban audio processing paper

No, it is not a DC offset in the traditional sense, it is changing the naturally asymmetric waveform of some sources. When you attempt to amplify a source the maximum you can amplify will be limited by the highest peak. If one side (positive above or negative below the zero line) is higher than the other that become the limit. By changing the phase vs. frequency relationship between lower and upper harmonics you can affect where the peak occurs.

I did not realize some people did that for recordings, I had only heard of it in the context of radio broadcasts. It is a way to allow you to compress the life out of a recording so it sounds equally bad whether you listen in a noisy car, on your phone earbuds, or as background music in a noisy office.

This paper has a discussion on effects of radio processing on source material, and describes why having excessively compressed music sounds worse after going through a radio processor:
Audio Processing in Radio paper

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#4

Thank you Chris for the insight. I ll read a bit into it, but I see this is not an issue with my mixes I guess, as I do mostly experimental electroacoustic music with a lot s of headroom and dynamics and no reason to sound like the “californication” album :wink:

#5

Now there is :slight_smile:

Except in the video it’s not a plugin. It shows iZotope Audio Editor so analysis as well as processing can be done offline, faster than realtime.

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#6

While I was at it, I have made a short video showing how digital-peak is affected by a phase-rotation:

The bottom oscilloscope show the sum of the tho phase-shifted sine waves (red and violet in the upper scope). Note how the signal symmetry as well as peak changes. Here an “optimum” is at a 135 deg (or -45 deg) phase shift:

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#7

I see Robin you don’t loose time :grinning: fantastic, I will try that on my next project

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#8

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