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-   -   Phasing?? (https://duc.avid.com/showthread.php?t=396990)

Raoul23 02-05-2018 09:24 AM

Phasing??
 
Just tracked a session using Slate drums and the blackbird expansion pack. I’ve recorded the midi to audio (separate tracks) looking at the waves they seem ok phase wise. I added McDSP AC1 on the kick out mic track and pressed the invert phase button To my ears the bass drum had more low end punch and was tighter. Here is the pick of the waves for the 4 bass drum mics

https://uploads.tapatalk-cdn.com/201...99d3077f7a.jpg

The green one is the outside kick mic.

Just wondered what you guys think, I know you guys will say use your ears, and to me it sounds better with the phase inverted. I’m just wondering if it’s my room playing tricks on me


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Tweakhead 02-05-2018 09:48 AM

Re: Phasing??
 
Phase looks ok, but try time-aligning them sample-accurate.
Use the top one as your reference point.
Align the the first zero-crossing of the others to match track one. (ie. after the first upward cycle as it crosses down over the zero line. Zoom right in, and nudge them by samples.

... and, of course, you'll still have to use your ears ;-)

... not exactly how things are captured in the real-world, but sometimes this can create a nice tight effect - if that's what you're looking for. In the real world - this is part of the art of mic-positioning. Put on a pair of head phones in the tracking room (so that you can hear the relationship between the inside and outside mics) while you adjust the mic position an inch or so at a time.

On a badly recorded kit I often have to do this, and then I use time-adjuster plug-ins . . . using my ears ;-) . . . to recreate the natural spacing between mics as I might have done in the first place.

Raoul23 02-05-2018 09:54 AM

Re: Phasing??
 
Quote:

Originally Posted by Tweakhead (Post 2473532)
Phase looks ok, but try time-aligning them sample-accurate.
Use the top one as your reference point.
Align the the first zero-crossing of the others to match track one. (ie. after the first upward cycle as it crosses down over the zero line. Zoom right in, and nudge them by samples.

... and, of course, you'll still have to use your ears ;-)



So make the red line straight, yep ??

https://uploads.tapatalk-cdn.com/201...1bc66ee762.jpg


Why does it sound better with the outside kick phase inverted??


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Tweakhead 02-05-2018 10:05 AM

Re: Phasing??
 
Quote:

Originally Posted by Raoul23 (Post 2473533)
So make the red line straight, yep ??

Why does it sound better with the outside kick phase inverted??

1. Yes.

2. Well right now it might, as they are not time-aligned, and they might be creating a pleasing phase-relationship EQ when inverted.

3. There are a few nice tools for doing this kind of thing in real time.

a. https://www.waves.com/plugins/inphase
b. https://www.uaudio.com/uad-plugins/s...-labs-ibp.html

Waves have a tutorial video on their plug-in:
https://www.youtube.com/watch?v=3TRkdY2OBB4


P.S. You do have your Delay Compensation enabled don't you ?

amagras 02-05-2018 10:31 AM

Re: Phasing??
 
Aligning the waveforms can help, reversing the phase too if the waveforms are aligned but opposed. If none of these work then it's time for something like this:
https://youtu.be/Momomj4ABNg

Raoul23 02-05-2018 11:02 AM

Re: Phasing??
 
Here are the 2 examples, one no phase invert and the other with the phase invert

https://www.dropbox.com/s/mr5iwj5qpe...nvert.wav?dl=0

https://www.dropbox.com/s/vqe8ins5li...nvert.wav?dl=0

Tweakhead 02-05-2018 12:01 PM

Re: Phasing??
 
Neither sounds right to me I'm sorry to say.
Try the alignment, and re-test.

P.S. What does just one mic sound like ?

Raoul23 02-06-2018 08:57 AM

Re: Phasing??
 
sorry my bad they had some plugins on.

Here are the 4 drum mics no plugins this time other than AC1 on the out side kick with phase invert active

Without phase invert active

https://www.dropbox.com/s/773ph4wvgs...nvert.wav?dl=0


With invert active

https://www.dropbox.com/s/m5uz8sc1xs...nvert.wav?dl=0

Drew Mazurek 02-06-2018 09:05 AM

Re: Phasing??
 
Phase is relative and frequency dependent. So when you "align" tracks, you're putting some frequencies in phase, some out, and some partially. So there will always be trade offs and compromises with no "right" answer. Experimentation is key.

cwsand 02-06-2018 10:19 AM

Re: Phasing??
 
Quote:

Originally Posted by Raoul23 (Post 2473528)
pressed the invert phase button

It's not inverting the phase - it's reversing the polarity. Phase/Polarity - 2 different things. Phase deals with offsetting time whereas inverting polarity reverses the positive and negative aspects of the waveform. They can be each be used to deal with frequency cancellation, but it's helpful to know the difference and exactly what each is doing. Companies tend to use the term "phase switch" for what is really a polarity inverter...


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