Cool Tricks with Phase Flipping!!

[Anderton]

I'm doing another Advanced Workshop video based around Sonar, and started experimenting with doubling tracks, inserting an effect in one and not the other, and throwing one out of phase.

 

Wow, there are some cool effects just waiting to be found!! I tried this with a phaser and cancelled out everything except the "phasing" sounds, it was like this "hyper-phasing" sound.

 

Also tried it with saturated drums. It took out the mud, left in the distortion, and regained the percussive nature of the drums.

 

It's also a cool way to compare emulations. For example, I was curious how the Cakewalk emulation of the SSL 4K bus compressor compared to the Universal Audio version. So I put each one in a track, set their controls to the same settings, and flipped the phase. I must admit I was pleasantly surprised at how complete the cancellation was.

 

I'm sure there are other cool effects just waiting to be found, but this is a start.

[ggm1960]

Now that sounds like fun! I imagine you're using the X1 version?

[Anderton]

Yes, X1. I like it a lot.

[blue2blue]

Since I'm (perhaps justly) infamous on another recording site for my pedantic insistence on the difference between polarity and phase, I'm just gonna shut up.

[Anderton]

Well, it IS flipping phase...just at all frequencies, like a polarity flip

 

It's only a true polarity flip if you have to take the wires off the battery, and put them on the other terminals.

[ggm1960]

Yes, X1. I like it a lot.

 

I've become rather attached to my Macs for music making in the last few years and am rather partial to Digital Performer and to a lesser extent, Logic Studio. I stalled out at Sonar 7 but still use it occasionally albeit mostly for figuring out songs my cover band plans to do. I'd used Sonar (and all the Cakewalk predecessors) pretty much exclusively for many years. My current PC is pretty old now and I've every intention of getting a new one next year, however, whether I'll be using it for DAW purposes and upgrading my Sonar remains to be seen.

[Anderton]

I'm definitely with you on DP over Logic for the Mac. Didn't used to be that way, but for some reason I really "clicked" with the DP interface changes in DP 7. The guitar effects didn't hurt, either

[WRGKMC]

Have you messed with the Sonitus plugin called Phase in Sonar Craig?

Lets you shift phase in varying degrees up to a full reversal.

Its especially cool when combining to identocal mono tracks to create some Psuedo Stereo widening.

If you use it with a chorus plugin or other time based plugin it really starts to do some cool things.

 

I mainly use it on either a guitar track that is being masked by phase bleedover in a live recording

or on drum tracks to get the drums pushing air in the same direction.

[blue2blue]

 

Good case in point. WRGKMC, Craig, I, and probably most of the others reading this forum probably know that WRGKMC really means a 180 degree delay at a given frequency, which is what such phase 'correction' tools do. But, unfortunately, far too many out there in home/small studio recording land don't. [EDIT: a much better way to have said that would have been 'a delay that creates a 180 degree shift at a given frequency.']

 

More info: http://en.wikipedia.org/wiki/All-pass_filter

 

(Sadly, the mathematical part of that article overchallenges what's left of my math skills -- which withered and all but died going to a high school which favored track championships over college prep -- my math teacher led our track team to a series of championships -- but couldn't even follow our Algebra II work. I was one of only 4 people in the college-prep class who could to the work in the second semester; we had no help from the teacher. The four of us got A's and everyone else -- who were completely befuddled and simply could not do any of the work, week after week -- got B's. I'm told that the school district in question, the Orange Unified School district in Orange, CA, has not improved. Sadder still, from my point of view, I never got myself back in gear to reinvigorate what the nice folks at the SAT seemed to think was a very high native ability. Mea culpa.)

[Anderton]

 

Have you messed with the Sonitus plugin called Phase in Sonar Craig? Lets you shift phase in varying degrees up to a full reversal. Its especially cool when combining to identocal mono tracks to create some Psuedo Stereo widening. If you use it with a chorus plugin or other time based plugin it really starts to do some cool things. I mainly use it on either a guitar track that is being masked by phase bleedover in a live recording or on drum tracks to get the drums pushing air in the same direction.

 

 

I've messed with it a little, but mostly use Channel Tools for that sort of thing...nonetheless, you've inspired me to re-visit it. Thanks!!

[MargeHowel]

 

It's also a cool way to compare emulations. For example, I was curious how the Cakewalk emulation of the SSL 4K bus compressor compared to the Universal Audio version. So I put each one in a track, set their controls to the same settings, and flipped the phase. I must admit I was pleasantly surprised at how complete the cancellation was. .

 

 

yeah, it's an old comparison technique. i though you even wrote about that yourself back in your "analog days"

[WRGKMC]

Polarity reversal can be hard or soft.

With two mics you can swap the balanced signal wires on one and you have reverse polarity.

If both mics are exactly the same distance from a sound source you should have one wave start in a positive slope and the other with a negative slope.

Both begin at the same time and both completely cancel another. The + going signal of one mic and the - going signal of the other occur at the same

time and they completely cancel each other out to zero.

 

As a note, its rare where the mics will have the exact same frequency responce or sensitivity levels and cables will often have different resistance

readings so the chances of both mics having absolutely identical signals being recorded isnt a realistic expectation so there will be some of the

two signals left mostly mid and high frequencies that dont cancel out so you wind up with a highly enemic, thin signal left you can still hear.

 

Most DAW programs do have a polarity reversal button (often caused phase reversal) thats supposed to do the same thing as reverseing the polarity of a cable.

It seems to work well enough for this and a hell of allot easyer than rewiring a cable. I do keep a few one foot low Z polarity reversal jumpers around so I can

just plug it into the end of a mic cable to reverse the cable polarity for micing a back of a combo, or reversing a drum mic, but it is easyer to just

punch the reverse button on a daw.

 

Phase shifting is a different thing because you have different start times on two waves.

 

You can delay the start time of one wave for example shifting a track so it begins 180 degrees later than the first track.

With a sine wave you have would basically have wave cancellation as a reverse polarity mic does but there will be one wave starting

before the other and the other ending after the first. With complex waveforms where things are happening on only 1/2 of the wave form

you dont get pure cancellation. Many guitar drive pedals have unsymetric waveforms so you wont get pure phase cancellation shifting a track.

 

The phase plugin I mentioned does not creats the same signal kind of delay/slapback effect track shifting does to my ears.

Maybe its because its adjustments are smooth and accurate at 1% intervals, but its more like gradually reversing the polarity of a

balanced analog signal with a rehostat type device instead of adding or subtracting start time to one signal.

 

I suppose I need to look into it more to be sure. I guess I could dig out my old dual trace Oscilloscope,

play back two identical tracks with the plugin running on one track and overlap the two beams and see if the

one track just shifts the time + and -

 

I keep picturing getting this picture in my mind though.

The plugin will let you shift the track + and - in phase

I'm wondering if I adjust the track say -45 degrees, the wave form begins at that higher 45 degree voltage instead of

zero prior to the untouched wave. Guess it really doesnt matter much but there must be something different done there if the

percentages of phase shift are accurate.

 

The other reason thats stuck in my head is A low frequency wave will require a different amount of time, to shift its phase percentage

in comparison to a high frequency waveform.

 

If I have say a 60 cycle waveform and shift it 45us to get a 90 degree phase shift.

Then I use a 120 cycle waveform the same 45us would cause a 180 degree shift.

This makes me think the plugin does something different than add and subtract time to shift the wave.

 

I dont know. Maybe I'm justy overthinking the whole thing but I think theres more to the plugin than just changing

start and end times. Its Friday, I'll have to rethink the thing Monday.