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Forums     Plugins     PHA-979 Phase versus time question

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Thanks Aleksey!

I don't know how you can find time to build these superb software gems which I suppose, must be a extremely difficult and time consuming job AND even still have energy to answer here, in K.V.R, and in Noisevault forums!

I perfectly understand the bass example concept as you explain it, but again...just how can I accomplish this with your plugin?

Doesn't seem to have a freq crossover to shift different frequencies by different amounts.

Or are you writing about a stereo bass track where each channel has a different phase, so by moving the phase on one channel by a cetain amount, you can achieve a perfectly coherent sound?

This would equal to my example above, moving a track in the timeline with reference to another fixed one.  In this case just the left or right channel of a stereo file.

I'm sorry...I really don't want to bother you with these questions, but this is one of the most unique plugins I've come across, (everyone knows somehow what an EQ, Compressor, etc. does to the sound), but it's a little bit more difficult to take the exact whole picture here.

I will download the demo to try to see for myself.

Thanks a lot!.

Rere, perhaps this fomula will help:

Delay (seconds) = Phase shift (degrees)/ (360 * frequency (Hz))

So you can see that for any given phase shift the delay is inversely proportional to frequency.  This means that if you choose to phase shift by 90 degrees then the amount of delay applied to the signal varies according to frequency so that the delay at 20Hz is 12.5ms, at 200Hz the delay is 1.25 ms, at 20KHz the delay is 0.0125ms.

I guess, phase-shfting PHA-979 does can be also described by means of group delay.  If I understand this concept correctly, it is the group delay which is affected.  When you do time-shifting only, the group delay is left unchanged.

Hi guys

I would like to verify if my understanding of the use of php-979 is correct.

It makes it possible to shift for example kik drum in a complete audio track forth or backwards by certain time.

If still mixing, this can be achieved in the audio editor, but the magic of pha-979 is that it can do the same on a mixdown audio track containing more instruments.




PHA-979 halves the time shift if frequency doubles.  For some it might be interesting to know that at 90 deg. phase shift, PHA-979 works as a Hilbert transformer.

This makes this plug-in totally different to delay plug-in.  You may see PHA-979 as a frequency-dependent delay.

PHA-979 won't cure every possible problem, but in a way it works, it covers more bases than frequency-independent time shifting (time aligning).  I.e. with the latter you may still get some 'problem spots' while with PHA-979 you can minimize this number to one or none.

An example of how PHA-979 works:

Let's take 100 Hz sine tone...  Its full period lasts 10 milliseconds.  Phase-shifting it for 90 deg is the same as time-shifting it for 1/4 of its period (2.5 milliseconds).  So, for 200 Hz 90 deg phase-shift will translate into 1.25 milliseconds delay.  And so on...

Since all frequencies get shifted for the same amount of deg. you won't hear any obvious change in sound because phase-relations between frequencies stay untouched.

In PHA-979 this is accomplished by building a special filtering kernel.  This has nothing to do with splitting the signal into several bands.

Thank you for the answer.  It explains that I was wrong.

Having read the description of PHA-979 and the related posts on the phorum I still can't imagine its practical use, but maybe it is a too advanced tool for me :)

Thanks again.


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