What is Additive Synthesis?
All right. So in the first segment, we talked about the basics of reactor getting through the structure, figuring out the windows, talking about macros and instruments and models and event routing and audio routing. All of that stuff. I mean, that's a really good foundation for building stuff in reactor. Now, what we need to do is take a step back and start talking about building waves, building signals, creating, uh, complex way forms from scratch. Essentially. And that's what we're gonna explore. Making an additive synthesizer in a subtracted synthesizer like we had before. We were taking content that was already harmonically rich and adjusting its tambor, adjusting its tone using a filter. Well, when we explore additive synthesis, we should talk about the first additive sent and arguably the first synth ever made. Uh, So what was the first additive synthesizer? Was it the camel audio chameleon? Really awesome. You know, software that had really great additive synthesis. Or maybe it ...
was the quiet K 5000 that came out like 1995. I mean, that was also a great additive sent in it, and it predates the chameleon. So, yeah, we're looking pretty good. Am I, Cynthy, That's right. There is an RMS, um, synth and the E. M s sent that came out in the seventies like those were Those were, like, the really, really definitive additive sense, you know, But in honesty, it was a trick question because the world's first synthesizer was the pipe organ. So the pipe organ interesting thing about the pipe organ. Well, we gotta talk a little bit about justify a and about his analysis of complex way forms and complex yeah, complex waves like he was, he said, You know, we can take complex waves and we can break them down into sine waves. So it's a very interesting concept. Basically, what we're saying is that sine waves of the building blocks of all complex sound now in a pipe organ. What's going on is when you play a pipe organ, it plays a bank of pipes. There's a pipe for each key, right, and the pipe makes a very sine wave like sound because we're blowing air over a pipe. If you play a flute, you also get something very close to a sine wave. So on organ you'd see these things like Let me go How do you go back? Sorry, I may have to edit this, but can I make an edit note real quick? We need to stay on the screen before we go to the foyer screen. OK, Okay. So the pipe organ, how does it work? And why was it the first additive synthesizer? Well, additive synthesizers. Basically, what they're doing is they're taking individual tones and adding them all together to make a complex tone. The way a pipe organ works is you have a pipe per key on your keyboard, right? And when you want to make a more complex Tambor, you would have a whole another set of pipes that are tuned differently that play along with the pipes that you had before. So in that way, the pipe organ was the first additive synthesizer. If we look at this keynote here, we can see that the their pipes up top. There's a keyboard down below and to the right and left of the keyboard. There are these white buttons when you pull them out that actually engages mawr pipes. So that's how a pipe organ works. Now, when it comes to additive synthesis in the theory of additives since synthesis. We need to talk a little bit about Joseph for you. So he determined Joseph Way determined that any complex wave can be broken down into sine waves. So this is a great graphic. I really love the way that this looks because it's a great representation of the theorem that he came up with. So what we're seeing is a bunch of sine waves, the blue waves or sine waves. The blue waves have individual tone. They have individual frequency. But when we add them all together, we end up with the red wave that we see there that looks a lot like a square wave. So we can also do the opposite. We can take individual sine waves and we can create complex waves. And that's the whole idea behind additive synthesis. Now, the other interesting thing about additive synthesis is that if we got additive synthesis good enough, if we had enough sine waves going at one time, you could recreate my voice. You could recreate me knocking on a table if we had enough control over these individual sine waves, their amplitude and their pitch, how they all add together, You can do some amazing stuff. There's something called additive re synthesis. We're going to talk about sampling a little bit later, which is where you just record a sound and play it back. But with additive re synthesis, what you're doing is taking a complex tone, actually analyzing it using FFT or Fast Boy Transform, which is four days. Little is the trick that we use to be able to see what the Sinus Wilken content of the wave is, and we could actually play it back. And it's not a sample playing back. It's not like a recording. It's a bunch of sine waves that are creating the sound. So it's pretty nuts because that means that you can literally take any part of my voice If you used additive re synthesis where it plays it back. Using sine waves, you could take any aspect of my voice and change it anything, which is it's phenomenal. I mean, it's like it's really like additive synthesis is so simple, and it's been around the longest. But it's also it has the greatest capability and newer additive since, like really showcase that. So the individual waves air called partials. Now, using some simple math, we can create our own partials. Okay, now most waves. We wanna have the ability to choose the harmonic in the harmonic Siri's So we're gonna talk about harmonic Siris in a minute. But it's something that happens in nature, and it's something that that we use a lot in synthesis. We're gonna use a lot of additive synthesis. And when you use it a lot in FM synthesis, we want to have control over tuning and fine tuning of those sine waves. We want to control the course tuning in the fine tuning, yes, so finding course dating control of amplitude. That's extremely important as well. Because those air to the basic things that we have with additive synthesis, what is the tuning of the sine wave and what's the amplitude? So how do we get the harmonic Siri's? Okay, so the harmonic Siri's is basically whatever your base frequency is like, whatever you're basing your entire wave off of the root of the wave. You take that frequency and you multiply it by 12345 on and on and on. It's a ratio, so you can think of it as one toe 12 to 13 to 14 to 1, and you end up with something like this. As you see down here, I've got it. Starting my first wave or what I call my first harmonic is to 20 hertz. So to two times to 20 is 4 40 right? And then we go to the next and you can see this is gonna be the harmonic Siri's starting from 2 20 So on the left hand side, you see the harmonic Siri's the right hand side. You see the 2 20 that's being introduced at each stage, so it looks pretty easy, but we're gonna make that happen in any sense. Now, Before we do that, though, I want to show what these ways actually look like. Okay. And one of the ways I'm going to show it is by opening up my favorite dog logic. And I have this e que with an analyzer built in, and we're gonna actually see the harmonics of these individual waves using the since we just made. Why not? So here's a sawtooth wave. When I play a sawtooth wave, it's showing us the harmonic series of that sawtooth wave. Now, if I can get it is close. Gonna get close I canto 100 because we get to 100. We can very easily see these harmonics showing. So we see one at 100 she won a 100. We see one of 500. So it's gonna be 102 103 104 105 100. You see it very slightly. Slope off and that's a sawtooth wave. And sawtooth waves are often used in subtracted with six. They have so much harmonic content, but that's all. Harmonic. Siri's 102 103 104 105 106 100. Now, when we start talking about triangle waves and square waves, let's check out a square wave real quick. Where's the 200? It's missing, right? So it's telling me that I'm getting all odd harmonics. So all the eat, even harmonics are gone and the odd harmonics or what we see when I go to a triangle wave a triangle wave is gonna look just like a square wave. But it's gonna have less content in the in the high end. So what's the purpose of a triangle wave? Well, a triangle wave. It sounds a lot like a like a sine wave, but a filter still affects it. Okay, so it's kind of Ah, it's kind of way that we fool ourselves into thinking that something is a sine wave when it's not. Now, what's kind of interesting? I'll pull it The saw wave Okay. From the sense that we created and I'm just going Teoh, turn on my filter envelope, pull my filter caught off all the way down So now we're gonna move the filter cut off using an envelope I don't just show what that looks like, so that is literally what's happening when we use a filter, you can see the harmonics appearing and disappearing according to how that envelope is controlling the filter cut off. Ah, uh, cool. So it's a good sort of basis in how these waves air created. Now, when we use our additive synth, we're going to try and create the perfect partial. So we're going to create a partial that has as much control as we can give it, um, for creating these individual sine waves that are gonna make this up. So of course, we haven't shown a sign with because I didn't have that built into this synth. Um, but I could just go in here. Um, I am doing reactor. Yeah, I'm gonna do in reactor. So going to my structure of you and just to just to show it, I'm going to control click built in module oscillator Perfect sine wave attach my gates, Gonna create no pitch attached the note pitch and I'm actually going to attach directly to the mixer. I'm bypassing the whole simple I'm just playing a sine wave. Just I can show you what it looks like when you play a sine wave. It's about as focused as you can get.