This is potent. I don't know that I've ever seen anyone on RUclips discussing this in detail quite like you have. It's simple and straight to the point. I used to obsess over correcting phase rotation using RX in the past. I still correct it...but It'd be interesting to see/hear the outcome of a rotation-corrected master vs one that contained a lot of rotation.
Great video as always - although one thing to note, phase is a function of frequency and can be rotated from 0 to 360 degrees. Polarity is however a function of positive or negative wiring, hence why on consoles and some audio devices you see polarity invert buttons to essentially swap the positive and negative audio signals. But we cannot rotate polarity, and we cannot flip/invert phase (at least outside the realms of simple waveforms such as sine, square et al).
@@panorama_mastering So, polarity is based on two states. In an AC circuit for example you have your positive and negative wiring (such as in a loudspeaker system). Polarity is either the red wire on the left terminal and black wire on the right terminal or the other way around. This is hence why we can't rotate 'polarity'. And this is where Polarity as a term has its limitations. Phase however, is essentially just based on delay by 0 to 360 degrees for 1x rotation (number of rotations could be infinite). With complex waveforms, if we shift the signal by 180 degrees such as to attempt to cause a total destructive interference or cancellation/null between the two signals, this wouldn't happen. However with polarity, it would as polarity does not care about the time-domain although phase does. Now you can test this yourself, if you get a plugin that can 'rotate' your signal in terms of phase, rotate a complex waveform by 180 degrees, pi or 3.148... and try to sum with another signal that is untouched, you'll find that a total null is not possible (although if you try this with a simple waveform that has the same cycle over and over, you would achieve a full null). This is because 180 degrees of phase rotation does not equal to an inversion of the audio signal, but instead just by how far you have delayed this signal. However in the above test, through inverting the polarity instead as opposed to rotating the phase of this duplicated audio signal/track, you would be able to achieve a complete null. Hopefully this shows that phase and polarity despite some similarity are two separate things which often us audio guys mistake for being the same, or at least two concepts which are interchangeable. I've tried doing a quick google search to help give you something more 'visual' in terms of diagrams, this little blog post seems to do the job well: audiouniversityonline.com/polarity-vs-phase/
Awesome; thanks for the explanation; that's very reasonable and certainly expands further on the basis of the theory I'm exploring here; Muchly appreciate your openness to share this!
@@panorama_mastering hey man I’m on this planet to try learn and hopefully share as much as I can myself and NGL I want to see you become the number 1 source for ‘nerdy’ audio information and techniques!! Really love your style of presentation of information - you have a really engaging character which a lot of people on this platform do not have - not least your existing experience in producing, mixing and mastering music really gives you a lot of credibility. But also despite doing an audio degree, masters in acoustics etc… from time to time I often find I learn most from your videos than anyone else’s on this platform!
Hey Matthew; thank you kindly for the support! I'm hoping this channel can continue to grow too! What's your email; I'd love to tee up a call with you leading into some future stuff I'm planning for the channel.
Holy shit! I’ve been trying to find a solid answer to that filter phenomena for years now. I always knew it had something to do with phase but I have never heard it explained in this much detail. Boss level!
Yeap! That was actually an ACCIDENTAL biproduct; when I was researching for this video; I thought I was going to set up a bunch of tests and debunk my own BS... turned out I was right all along.
It would be interesting to see the loudness, in units of LUFS or RMS, for those phase rotated waveforms. I would also be interested to see a loudness comparison where the peak is normalized to unit gain after the phase rotation. Basically, could we optimize loudness with the phase coherency? Might not be useful for mastering, but could be interesting in a phase controlled environment like synthesis.
Hey Astrobear; to answer "Basically, could we optimize loudness with the phase coherency?" YES! you certainly can; there's a video iZotope put out with another mastering engineer that does this in iZotope RX Audio Editor!
I’ve seen mastering engineers on RUclips rotate masters in RX to increase digital headroom, but I never saw much of a benefit when trying it on my tracks. Maybe it would help if you had a lot of asymmetrical waveforms in your mix or DC offset. (Fabfilter’s L2 has a convenient DC offset button so you don’t even have to worry about it)
Asymmetrical waveforms and DC are not the same thing actually, but I had a question about the iZotope video that I recently saw as well. I used the phase rotation function in rx recently, as the first step before going into any mastering processing. I noticed it gave me a lot more headroom, it reduced the highest peaks quite a lot, but I also noticed that transients started to smear a little bit and I got very noticeable preringing. I this just an effect of phase rotation? Since it shifts the harmonics that make up a waveform away from each other?
@@robbeservaes3625as far as the manual of RX states, there should be no sonic difference whatsoever, phase rotation is related to the absolute peak value of the waveform...
@@eccentricworx yeah I read that too, left me very confused, because there definitely is some noticable preringing on stuff like kicks etc. I've decided to stay away from this on full mixes, unless absolutely necessary, but might do it on individual tracks if I can't hear any artifacts or transient smearing when applied.
@@robbeservaes3625 interesting, I fix phase rotation before every mix, never noticed anything like that. But I fix phase shift and phase spectrum on multi-mic tracks with tools like Auto-Align and Pi too...
I must admit I still don't get this! Basics - a longitudinal soundwave is converted to a voltage that goes positive with the compressions and negative with the rarefactions, tracked over time we can see this changing voltage on an oscilloscope. This up/down track is then digitised by sampling the voltage a few thousand times a second, and we get the ubiquitous graphic shown in most sound software and plugins. In my head, I see this as a purely two-dimensional process; voltage/bit depth and time - X&Y. In order to have rotation we'd need a W axis which doesn't exist as I understand it... If anyone can point me to an appropriate article it would be much appreciated.
1) Don't try and understand it from this video, or any other video on phase involving people who go straight to mixers. This is basic signal processing, and it is completely conflated and confusing in this video. 2) Forget about waves before understanding signal processing. Essentially, the microphone output is a signal anyway, although it is taken out of a field. 3) When dealing with phase, we have already made an assumption about working in the frequency domain with steady-state sinudsoidal signal, meaning that we are looking at a particular signal for each frequency, which started infinitely long ago. This falls out of the underlying Fourier transform that the signals have undergone. 4) A sinusoidal defined via a function has its own defined phase, but when measuring phase, it will typically relate to a system, such that the phase indicates what has happened to the input signal as it is output of the system. 5) The phase is thus seen by comparing the steady state sinusoidal on the output with the steady sinusoidal on the output. If they for example they align (perhaps with different amplitudes) the phase will be zero or a multiplum of 360 degrees. 6) Looking at only a single frequency can be misleading as seen from 5) as the phase is ambiguous. It should therefor be seen over the entire frequency range. 7) A polarity flip is a particular phase situation, where whatever the phase was before, it is now shifted 180 degrees at all frequencies. This is how a sign inversion can be included into the phase, as it does not affect the magnitude. Think for example of how a real positive number can be rotated 180 degrees onto the real-axis, where it is now negative. The phase rotation is exactly that, only operating on complex numbers instead for the so-called phasors that contain the magnitude and phase for each frequency.
Ah, so I'm making it more complicated than it needs to be by trying to figure it out in three dimensions! The 'rotation' is purely a phase shift along the time axis that puts it several degrees ahead/behind compared to the original waveform.@@Rene_Christensen
@@timothybondaudio In some sense, but don't think of phase only as a time delay. The phase is primary, and from it different delays can be found, such as phase delay and group delay, but there are steady-state delays, so they don't necessarily represent the latency of the system. So there is more to phase than just pure time delays.
Thanks for the video. Could you tell what better to do low shelf or low cut when mastering trap on usual monitors where i do not have possibility to hear difference on the low low end. Will appreciate the answer. Tbh i am afraid that low shelf wont be enough to remove low 20hz.
Whatever you need to do to the frequency response is more important than not causing phase distortions. Again, as shown, EQs ARE phase distortions. That being said, how do you expect to adjust something you can't hear?
Yeap; I'm looping back on the Orion; Dangerous are an incredible company; but I had some issues with the unit; and all the way from here in Aus; the downtime to get it back up and running was too long for my liking; I'll be updating my AD on my next studio move towards the end of the year;
Go back to your mix and fix things. Mastering is for masters ... It's the final lap of the marathon, there's no big changes there. You'll just make a bigger mess ... :)
OMG. Mastering in the box with plugins. 🙈. Phase rotation on a finished mix?? WTF? I phase align every track but 1 in all my mixes. Don’t be messing with the phase of a full mix for God’s sake. And listen and understand what REAL mastering engineers like. Bernie Grundman, Mark Wilder, Ted Sterling, Bob Katz, etc do. Those guys are Real Mastering engineers. I find these posts to be detrimental to music of real quality being produced. 🙈
This is potent. I don't know that I've ever seen anyone on RUclips discussing this in detail quite like you have. It's simple and straight to the point.
I used to obsess over correcting phase rotation using RX in the past. I still correct it...but It'd be interesting to see/hear the outcome of a rotation-corrected master vs one that contained a lot of rotation.
Great video as always - although one thing to note, phase is a function of frequency and can be rotated from 0 to 360 degrees. Polarity is however a function of positive or negative wiring, hence why on consoles and some audio devices you see polarity invert buttons to essentially swap the positive and negative audio signals. But we cannot rotate polarity, and we cannot flip/invert phase (at least outside the realms of simple waveforms such as sine, square et al).
Good thoughts; can you expand on, "we canot rotate polarity... (at least outside the realms of simple waveforms)
@@panorama_mastering So, polarity is based on two states. In an AC circuit for example you have your positive and negative wiring (such as in a loudspeaker system).
Polarity is either the red wire on the left terminal and black wire on the right terminal or the other way around. This is hence why we can't rotate 'polarity'. And this is where Polarity as a term has its limitations.
Phase however, is essentially just based on delay by 0 to 360 degrees for 1x rotation (number of rotations could be infinite).
With complex waveforms, if we shift the signal by 180 degrees such as to attempt to cause a total destructive interference or cancellation/null between the two signals, this wouldn't happen. However with polarity, it would as polarity does not care about the time-domain although phase does.
Now you can test this yourself, if you get a plugin that can 'rotate' your signal in terms of phase, rotate a complex waveform by 180 degrees, pi or 3.148... and try to sum with another signal that is untouched, you'll find that a total null is not possible (although if you try this with a simple waveform that has the same cycle over and over, you would achieve a full null). This is because 180 degrees of phase rotation does not equal to an inversion of the audio signal, but instead just by how far you have delayed this signal.
However in the above test, through inverting the polarity instead as opposed to rotating the phase of this duplicated audio signal/track, you would be able to achieve a complete null.
Hopefully this shows that phase and polarity despite some similarity are two separate things which often us audio guys mistake for being the same, or at least two concepts which are interchangeable.
I've tried doing a quick google search to help give you something more 'visual' in terms of diagrams, this little blog post seems to do the job well: audiouniversityonline.com/polarity-vs-phase/
Awesome; thanks for the explanation; that's very reasonable and certainly expands further on the basis of the theory I'm exploring here;
Muchly appreciate your openness to share this!
@@panorama_mastering hey man I’m on this planet to try learn and hopefully share as much as I can myself and NGL I want to see you become the number 1 source for ‘nerdy’ audio information and techniques!! Really love your style of presentation of information - you have a really engaging character which a lot of people on this platform do not have - not least your existing experience in producing, mixing and mastering music really gives you a lot of credibility. But also despite doing an audio degree, masters in acoustics etc… from time to time I often find I learn most from your videos than anyone else’s on this platform!
Hey Matthew; thank you kindly for the support! I'm hoping this channel can continue to grow too! What's your email; I'd love to tee up a call with you leading into some future stuff I'm planning for the channel.
Holy shit! I’ve been trying to find a solid answer to that filter phenomena for years now. I always knew it had something to do with phase but I have never heard it explained in this much detail. Boss level!
Yeap! That was actually an ACCIDENTAL biproduct; when I was researching for this video; I thought I was going to set up a bunch of tests and debunk my own BS... turned out I was right all along.
It would be interesting to see the loudness, in units of LUFS or RMS, for those phase rotated waveforms. I would also be interested to see a loudness comparison where the peak is normalized to unit gain after the phase rotation. Basically, could we optimize loudness with the phase coherency? Might not be useful for mastering, but could be interesting in a phase controlled environment like synthesis.
Hey Astrobear; to answer "Basically, could we optimize loudness with the phase coherency?"
YES! you certainly can; there's a video iZotope put out with another mastering engineer that does this in iZotope RX Audio Editor!
@@panorama_mastering thanks for replying, I will seek out this iZotope video ❤️
I’ve seen mastering engineers on RUclips rotate masters in RX to increase digital headroom, but I never saw much of a benefit when trying it on my tracks. Maybe it would help if you had a lot of asymmetrical waveforms in your mix or DC offset. (Fabfilter’s L2 has a convenient DC offset button so you don’t even have to worry about it)
Yeap; it very common when there is a great deal of offset! I've used that tool too!
Asymmetrical waveforms and DC are not the same thing actually, but I had a question about the iZotope video that I recently saw as well. I used the phase rotation function in rx recently, as the first step before going into any mastering processing. I noticed it gave me a lot more headroom, it reduced the highest peaks quite a lot, but I also noticed that transients started to smear a little bit and I got very noticeable preringing. I this just an effect of phase rotation? Since it shifts the harmonics that make up a waveform away from each other?
@@robbeservaes3625as far as the manual of RX states, there should be no sonic difference whatsoever, phase rotation is related to the absolute peak value of the waveform...
@@eccentricworx yeah I read that too, left me very confused, because there definitely is some noticable preringing on stuff like kicks etc. I've decided to stay away from this on full mixes, unless absolutely necessary, but might do it on individual tracks if I can't hear any artifacts or transient smearing when applied.
@@robbeservaes3625 interesting, I fix phase rotation before every mix, never noticed anything like that. But I fix phase shift and phase spectrum on multi-mic tracks with tools like Auto-Align and Pi too...
Hey Nicholas, love the video but I don't have a 4k monitor and the waveforms at 3:36 are barely visible to me. Keep up the good work.
Thanks mate! Sorry, I only realised this AFTER I had uploaded and published **Facepalm**
With all this said Low Shelf Filters just sound better IMO, especially for Mastering.
Agreed;
I must admit I still don't get this! Basics - a longitudinal soundwave is converted to a voltage that goes positive with the compressions and negative with the rarefactions, tracked over time we can see this changing voltage on an oscilloscope. This up/down track is then digitised by sampling the voltage a few thousand times a second, and we get the ubiquitous graphic shown in most sound software and plugins. In my head, I see this as a purely two-dimensional process; voltage/bit depth and time - X&Y. In order to have rotation we'd need a W axis which doesn't exist as I understand it... If anyone can point me to an appropriate article it would be much appreciated.
1) Don't try and understand it from this video, or any other video on phase involving people who go straight to mixers. This is basic signal processing, and it is completely conflated and confusing in this video. 2) Forget about waves before understanding signal processing. Essentially, the microphone output is a signal anyway, although it is taken out of a field. 3) When dealing with phase, we have already made an assumption about working in the frequency domain with steady-state sinudsoidal signal, meaning that we are looking at a particular signal for each frequency, which started infinitely long ago. This falls out of the underlying Fourier transform that the signals have undergone. 4) A sinusoidal defined via a function has its own defined phase, but when measuring phase, it will typically relate to a system, such that the phase indicates what has happened to the input signal as it is output of the system. 5) The phase is thus seen by comparing the steady state sinusoidal on the output with the steady sinusoidal on the output. If they for example they align (perhaps with different amplitudes) the phase will be zero or a multiplum of 360 degrees. 6) Looking at only a single frequency can be misleading as seen from 5) as the phase is ambiguous. It should therefor be seen over the entire frequency range. 7) A polarity flip is a particular phase situation, where whatever the phase was before, it is now shifted 180 degrees at all frequencies. This is how a sign inversion can be included into the phase, as it does not affect the magnitude. Think for example of how a real positive number can be rotated 180 degrees onto the real-axis, where it is now negative. The phase rotation is exactly that, only operating on complex numbers instead for the so-called phasors that contain the magnitude and phase for each frequency.
Ah, so I'm making it more complicated than it needs to be by trying to figure it out in three dimensions! The 'rotation' is purely a phase shift along the time axis that puts it several degrees ahead/behind compared to the original waveform.@@Rene_Christensen
@@timothybondaudio In some sense, but don't think of phase only as a time delay. The phase is primary, and from it different delays can be found, such as phase delay and group delay, but there are steady-state delays, so they don't necessarily represent the latency of the system. So there is more to phase than just pure time delays.
Phase is not time based
Ummm, everything in sound is time-based.
@@griffini19
Thanks for the video. Could you tell what better to do low shelf or low cut when mastering trap on usual monitors where i do not have possibility to hear difference on the low low end. Will appreciate the answer.
Tbh i am afraid that low shelf wont be enough to remove low 20hz.
Whatever you need to do to the frequency response is more important than not causing phase distortions. Again, as shown, EQs ARE phase distortions. That being said, how do you expect to adjust something you can't hear?
Hey Roman,
The core to this answer is WHY do you want to cut these frequencies completely?
I suggest using a low-shelf if you want to attenuate them;
Can't see the Dangerous AD+ in your rack anymore - you using a different unit now?
Yeap; I'm looping back on the Orion;
Dangerous are an incredible company; but I had some issues with the unit; and all the way from here in Aus; the downtime to get it back up and running was too long for my liking;
I'll be updating my AD on my next studio move towards the end of the year;
@@panorama_mastering Ahh that sucks, I heard a lot of people had issues with powering it up.
Any thoughts about linear phase EQs ?
They have their place! Certainly; but there are trade offs! Check out Dan Worral's video on Linear Phase vs Minimum Phase EQ's
Love your content and you’re entirely correct , I’d like it even more if you just slowed your speech a bit , apologies in advance : you speak fast
THANK YOU! I wish I could slow my speech too! I TRY!
You can always slow down the video. I prefer his pace to long, drawn out speakers.
Very interesting but I don’t understand 🤣
nerd
Cheers m808
Go back to your mix and fix things. Mastering is for masters ... It's the final lap of the marathon, there's no big changes there. You'll just make a bigger mess ... :)
OMG. Mastering in the box with plugins. 🙈. Phase rotation on a finished mix?? WTF? I phase align every track but 1 in all my mixes. Don’t be messing with the phase of a full mix for God’s sake. And listen and understand what REAL mastering engineers like. Bernie Grundman, Mark Wilder, Ted Sterling, Bob Katz, etc do. Those guys are Real Mastering engineers.
I find these posts to be detrimental to music of real quality being produced. 🙈
Please let me know
Where's the issue with using plugins for mastering?
How is this detrimental to music of real quality?
@griffini19 We're all glad that Bernie Grundman, Mark Wilder, Ted Stirling and Bob Katz didn't take your approach to physics and education.