Phase Cancellation & Additive Synthesis
Now we're going to be talking about added is that this is we have this lovely presentation already kind of built up to sort of talk about what we're going talk about so before we think it was actually a whole bunch of stuff that still actually basten's attractive but this is not talk about that kind of leave them do all of it begins the idea phase cancellation and this could be a lot of fun but also has a everything to do with what a re spaces becoming we kind of did a little bit of it already, but I want actual explain what that is and it's really interesting stuff uh super so I kind of already that but has moved kind talk about began with this time in been sort of context on face cancellation, which will be quite a big deal and then talk about harmonics and these just harmonics and harmer when which will sort of get to play the actual meat of what I have this this is and then we'll talk about kind of had a deuce attractive type things but with an added edge which typically is mostly ...
is mostly just tow having higher control over things that you wouldn't normally if you're just using regular strike of stuff and also like I said before about how to fact that's attractive for this is involved in every other kind of this is regardless but it is in control car like a little example sound that we did a minute ago with some of you might have no one I did, but mostly probably didn't on that we'll find out why? Because it's awesome, but everything in recent is this a big part of easing harmer? Yeah, okay, and then we'll be doing that too later, but for now, let's actually get into doing stuff that we're doing. So, um on the screen here, I've got kind of just rebuilt well, they had going on earlier and you might notice I have a citrus opened because I'm still talking about sort of attractive stuff and her mother were talking about face cancellation, so face cancellation has to do with the idea of phase and just sort of the story what phase means I was going to sort of I was a little opening of the sign weighted right here and then if I sir change when it begins in the movement of the isolation that's basically just changing the face of the way form it's really all there is to that face cancellation comes from some interesting interaction between when you add together away forms, so demonstrate this some kind of cheat a little bit I might actually use away form, but I am going to use but animation clip in l a faux mode which shows us uh well I guess actually like we said before it is still a way for because l if I was just a little frequency oscillation which is still a wave so here we have a nice and I sort of sort of sign waving type thing it's a perfect sign way because I didn't make a perfect but whatever um when we look at a sign with any kind of late for when we kind of measure what we're looking at we have a positive and negative value center is actually zero that's where the speaker is that its original center sort of non moving position and then it moves out positive back in negative and then there's about the plans we got like we discussed in the very beginning of today's classes stuff but we can add together more than one way for him and if we do this it could be measured actually pretty directly plus one plus two plus one we get plus two minus two together and the able judah's increase that just means that it goes farther up and from it out but what happens when we move one of these way forms out of phase which has been described earlier it's changing when it begins in the end of adding together sort of off off kilter way forms face cancellation is sort of the answer what happens which is to say that if you had a positive and negative you get zero and if you were to add together away form that it's perfectly out of phase you will get zero signal and we could actually demonstrate this immediately by loading up kind of any okay keep any sound at all and in the options you can say reverse polarity that's what that is the negative positive businesses polarity so where what was once positive is not negative it was now what was negative is not positive and if you add to that you get it you try and play them you get silence so that's what we have in the course of it perfectly out of phase and completely aligned if I move it you little bit out of out of where it wass I'm keen we get sound but sounds kind of phasing this by the way it's kind of our phasers do so now this is what happens when you have the same sound kind of out of phase but what if we're playing the same sound sort of better both in phase but one of them is slightly faster or a slightly different pitch that's not speed this is big area so it's still a sign wave it's still starts in the same phase but the other different pitches which means that over time it gets completely out of face but then it comes back around to be completely in face that means it kind of also its phase it goes with televisions and face elevation with advice, and this means that it's going become quieter than normal than quieter in the normal over and over again, rhythmically as determined by the notes that were playing that sounds kind like this that's what it sounds like what speakers to start um, I don't know anyone who could hear that in the and the stream that people in the room heard that doesn't. That was fun. Um, so that's, what I what I just did there was I played I know another note like this now on that note into playing together, and they do what that's sort of the fake version of it did in the playlist where it rhythmically cancels this is the heart of every everything that we've that we've ever called a re space. Reese was a person, I think back in the day, I don't remember when or why, but uh some guy I figured it out, maybe basin and that became sort of like the heart of the base for a very long time it's still kind of is but playable across all all sort of based music generous typically this is that with this always kind of just kind of thing, we usually applied with a concept of unison, the bigger the difference, the higher the pitch difference between the two tells the faster it happens also the higher the pitch theme, the faster it happens because it gathered it means faster way for so it happens faster, others to that now the concept of the superstar that I was gonna talk about about the idea of having to deal with face cancellation so when we have a lot of units, invoices way have a very sort of deep um sort of mess now theories on why this sounds the way it does is not just because of the one frequency oslo we were doing with the sideways, but because all the other harmonics in the sol wave are all face canceling and because they're they're higher harmonics, higher talent hire purchase higher frequency they're all faster, which means we have very high frequency phase cancellation and it creates this sort of toad mess that gets us the super zone that's all very faizi and phasing this is it is going to be a big is actually very, very important thing about a lot of sound is that because something sounds like too sharp that's because it's very well in the phase than that kind of thing we want to tell the softer the kind of want to find ways of getting it out of phase and he is and there's a pretty good way of doing that now the reason initially why I want to talk about face cancellation is because of the idea that that was really about playing to doubts right side wave it was my wife and if I kept flying notes you find that pretty much every single one of them face cancels except for the way they didn't cancel the fact it played get the other and that's because the active of the fundamental which is to say but lois town they're playing is the first harmonic and harmonic is a multiple of the fundamental, which means that when it's played together will not create face cancellation and this is where we start to get away from the concept of attractive to this is because face cancellation is very natures canceling the sound canceling out so frequencies and gets so attractive is taking away from it which the carbon idea that you might not think about is belonging this practice of this but it does very much so because you're subjecting except a warmer adding together harmonics because that's not scratching it's actually adding to the single something that wasn't there before and the way that doesn't take anything away at all and as it turns out, um if you kept adding sine wave for my next on top of stuff just keep going, keep going, I'll open up it up it up eventually you'd add up to a sol wave and this is sort of the first example an idea that want to explore utilizing advances incisors like hover if I were to weigh have our foot a little town first, I've second active, so I'm so and so forth weii get someone that we actually are really able to distinguish individual towns anymore. It just sounds like this all with and there is almost no distinction between herman's idea of us always, which is actually not that it's one voice, but that it's actually it's five hundred sixteen voices of sideways to create the saw versus saw present and attractive since pictures kind of essentially a recording of us always it's how some of them doing that, but watch, watch that's what? I have had this attractive, so always look at the harmonic content, and then we'll get the harmonic content of harmer players always through thermal visualize in there, and we see it's identical. And this is the entire tenant behind the idea of adding that this is, is that and any sound that we have built up of individual harmonics. And if we know where all the harmonics are, and what know what, what pitching level, and all that and phase, and all these things that we can play all of them as individual sideways, and build that sound from nothing, and pretty much was up, how did this is works, but, oh, man, does that ever not just stop there may be thinking why why would you do this and south unimaginably complex and ways to do so relatively simple things like what's the what's the benefit of having I saw a wave of the build up of a whole bunch of different sideways versus just having a solid why? Why? Why? Well, for most simplistic applications like you know, doing a super soft pluck you might not care might not really matter but the whole point and I did some business is that again I mentioned it's not the idea that you have one voice is not one voice anymore it's five hundred sixteen individual voices and he sees everything that harmer does the filters it's phaser ah, you know the weirdness isn't the units and even everything it does it is all about controlling three primary aspects controls the volume, the pitch in the phase of all these five hundred sixteen harmonics and through that we could do a lot of predictable sort of so attractive fending like that filters I mentioned but then we can also do things that's attractive filtering could just never imagine because we have individual control over all these things you have to really keep that in mind while work sort of showing off the stuff is that it's really not about a single thing? It's like the hot hive ah high voice kind of idea just like when I went up to eun is, um my nine years unison it's not nine voices nine times five hundred sixteen voices just four thousand six hundred forty four and, uh a lot of voices um we'll start with the filtering that because that's what some of the most basic ideas attracted to this is to try to see what we could do with it in terms of at it is this is more so let's sort of look at what it's doing when we're moving around so we're the what's happening it is not cutting off audio or it's sort of, you know, making a split like that what is doing is it's moving across and telling the harmonics not the play anymore or to turn back on as a cutoff moves through the frequencies it has a number of different benefits like I mentioned phase distortion in the last segment when that were doing cross crazy filtering inside the inside thank you and, uh phase distortion comes from how each use tend to do their business and also feel there's any kind of real time application of filtering is done through a process called minimum phase in the middle of the phase filtering and the other can't science is something called linear face which you might have heard before is part of the difficulty equalizer a little in your face kind of idea and it's to get away from the kind of problems that president we need you we don't face bad because what happens is that in order to make it like a dipper filter whatever it actually is using phase cancellation by changing the phase of the frequencies too cut out or accentuate part of where I wear whatever you're doing, I kind of think through very complicated things you will do very complicated sort of cuts this is why engineering like classes and schools will tell you not to do very intense cuts in equal answers because the more intense the cut, the more intense the phase change and that can sometimes cause face phase distortion even to spread static static changes. But then moving stuff around means that you're changing the face of a whole bunch of frequents a whole lot when you're moving stuff around and later when we talk about the terms of this issue realized why that's bad because as it turns out when you're altering the phase of something when you're moving it while playing, you're going to change the picture something as part of the reason why all that crazy filter that made the big narrow mess sound result that usually results and gnarly unusable sub frequencies because it the pitch is just crazy but in out of the universe because the filtering isn't doing any of that it's just telling the harmonica turn on and off wait you have this fast moving around filtering as you want and everything that's not being filled there it will be one hundred percent stable all the time as if it were letting your face it's still happening live which is actually a very powerful thing that I come to come to show you when we talk about recent this is and that kind of deal not only that but um the idea of the filter that we're using right now a little past what they're even has a residence no way this is like really beyond them agree because evens the fact is that this isn't is mimicking you know a lot of hardware that does that kind of thing this is and this is mimicking the requirements of a filter to do his job because what the what the residences is another sort of setting following around the cut off that says at the caught off these air going to be a slightly louder than it wasn't it a go and you can even change that you can change how wide the section is ah war ah war around you gonna move where this on war in your relative to where the cut off is which is not something you really can do with normal filters beyond that there's even the shapes that we have access to our mimicking sort of the expected shape of the various voters before you know the four kinds but lo ban, ban, stop band pass high pass that kind of thing in the various different kinds. But then you can also customize and make your own builder shapes which are not really related to any of the four, unless you want them to be wait. And my most fun actually is tio do the same thing with the residents, but where you can change sort of shape of the residence, but not just the field. There is this kind of honor off, but the residents it's positive in vegas, we could make it louder and quieter, and with the weird line type of obstruct that was stuck with their, which creates you just have again the idea of control because we're controlling the parameters of the individual harmonics, the pants, the phase and volume of whatever we can. We can have individual sort of very individual control over everything we're doing, and the sort of the limitation of what you could do with that is based on just the idea that, you know you can do something with it and that's kind of a lot. Ah, even this is mimicking what really phaser does to a single where because it's it's, playing a very fast version, passed the later version of the same song that gets itself to create space cancellation in a very interesting way it creates more or less this sort of behavior in it and harbors mimicking this by just making moving rolling filters that are going toe move in a certain way and then much like the real filter that the focus we had here presently we could change whatever you want about it even just by the controls that a president like you know how fast booth what direction it moves council keyboard track on instead of just being in the same spot all time can also change the with the change like the waiting ah and obviously how much is being a part of it can also again much like with other change the shape of this does weird things you know, very interesting effects on things like that and that would happen there's also the frequency mode where ever we were saying about the three parameters phase pitching via whatever the phaser is doing what it's doing about controlling the volume but then we're just taking its application of what is doing it with seven five and if I were playing in the pitch and does usually unusable things but it's kind of interesting kind of here for a second it does seem kind of cool stuff and they experiment with that you can get very extremely unique sounds that they're really possible otherwise and that's, really the name in the name, sort of the name of the game in my mind about using armor using out of this. But this is a process. Is that it's about doing stuff that is one hundred percent impossible? Otherwise, it's, not it's, not the matter of mimicking something that something else can do, and he's doing it in a way, that's accessible, like diligently, like after him. So this is the whole, the whole process that's designed to mimic what an alarm hardware can do, but do it in a way that gives you more control. It's easy doesn't cost a billion dollars, and it isn't pain in the ass to dio. This isn't about the one step that one hundred percent in exist before the process was something that could be done digitally, and this is why I love it as a process. It's a good time.