FM Synthesis with Native Instrument's FM8 and the Ableton Operator
Welcome back. This is less than three for Class one of the intro to synthesis and sound design. It's Lamb Academy For this lesson, we're gonna be focusing on building off of our previous lessons and subtracted synthesis and getting into a more advanced, slightly more technical form of synthesis called FM synthesis. F M stands for frequency modulation on what we know about frequencies and modulation is that generally are modulation. Generators and subtracted synthesis are, LF owes and envelopes they generate slow modulation, assigning other parameters to move up or down over time. Um, frequency modulation works the same way, but with one critical difference. FM synthesis pivots around audio rate modulation. So what that means is instead of, ah, slow LFO, where you can hear sound in between every cycle you can hear each peak and every crest of each. LF owes modulation stage. In this case, the LFO or another in the FM context are modulators. Signal is running at an audio rate meaning far ...
too fast for us to actually hear individual cycles, but more so just overall texture generator. So let's take a look inside of Able Turns Operator, which is their FM synthesizer um to investigate. First of all, what FM senses is a concept, and then I'll give you some tips for how to make a couple cool patches. So inside of the operator, we have four oscillators. These are actually technically called operators with a lower case. Oh, because this is FM synthesis FM synthesis terminology includes the operator as, ah, primary sound generator, and what the operator does does it works like an oscillator where you have a volume and you have a way of form. But in addition to just a wave form selection on a level you have four critical variables. First of all, each oscillator has to be routed into itself or into each other, and that happens through the algorithm. Other, also known as the routing matrix for the different oscillators outputs, thus evoking a carrier and modulator relationship. So what that means is, the carrier in this case is operator A. It's the bottom one of the stack, and therefore it's audible. If you look closely into this little stack, they're all connected together. What this means is that operator D is modulating. Operator, See is modulating. Operator be is then finally modulating our carrier operator A. The carrier is the operator that's transmitting the audio signal, whereas the modulators simply act as audio rate LF owes to provide texture and motion to our fundamental frequency that's generated by the carrier. So let's take another look at the different algorithm, for instance, something that's a little more complex, like this guy. For instance. In this case, you have to carriers that are both generating an audible signal, and they are in parallel, meaning that they're not affecting each other. Operator a an operator cr both generating a signal that's not related or interacting with each other at all. And then they both have their own modulation generators. So in this case, you have two different sine waves at different pitches, and then you'd be adding FM tow operator A here and adding FM to operator. See here. So that's how that's the first component of what makes an oscillator operator routing them into each other. Let's go back to the pure FM algorithm and we'll move on to what else makes an oscillator an operator beyond just routing capabilities in the algorithm section, we have three other functions, one of which is very important is that each of our operators have their own amplitude envelope. See how, as I select across these different operators, my detail panel is showing me discreet and unique envelopes. That's really important because this amplitude which is this parameter here you don't want to just leave it up and have it sitting static. You wanna have it be a triggered by by a note message, for instance. Maybe in this case, if I made this really tight every time I plucked a note this volume, we essentially would be, like up and down really fast versus in this case, every time I fucking know it, that's going essentially be kind of automating this amplitude of this modulator to slowly attack and then snap back down. So essentially, this is the amplitude envelope. In other words, the envelope for this game, Stage of the operators output so discreet envelopes per oscillator. That's number two. Number three course tuning. The course tuning component here gets to be a little more complicated, But all you need to remember is that if you can remember from lessons one into the way, the harmonic serious works. In the case of a saw wave, having every integer ordered harmonic. Let's listen to that really quick. That's interred your order to harmonics. To review you have. You can always look down in the lower left and see where in mousing to 67 to 68 to 67 plus plus 7 95 which is to 67 times 3 to 67 times four 1.6 to 67 times five. So what this means is that each of these is a multiplication of the fundamental pitch. This is what integer order harmonics really means. So how this relates to FM synthesis is kind of interesting. So they can do now was I can essentially take a sine wave which only has one fundamental and I can add another sine wave to it with the full sustained and I want to start to get into your order. Harmonics. Notice. I'm at course tuning one. This is what this is all about. Integer, order and, uh, see how each of those peaks were lining up perfectly with the integer harmonics of the saw wave. Yet these air only sine waves. This is where FM synthesis becomes amazing and powerful, and so beautiful. We have the ability to do here as we can use course tuning to multiply the fundamental pitch. So what this means is watch. Here's my sine wave. Let's go times two times, three times for times five and so on. So the natural harmonic series, which we learned a lesson one is the foundation of all Western music being to 1 as the active 3 to 2 as the perfect 5th 4 to 3 as the perfect fourth. 5 to 4 is the major third, 65 as the minor. Third, we have a major second in 76 That is the frequency interval of all of these major notes and intervals of the Western scale. So essentially, when we play a saw wave or a sine wave with a lot of FM, we're getting all those major and minor notes. Are intervals of the western scale pretty interesting, huh? And course tuning allows us to essentially aim the output of these oscillators to particular parts of the spectrum. Watch this five, see how it starts higher. 12345 Because I have multiplied. This is essentially is like an ability to aim the modulation to particular intervals above the fundamental pitch. So that is the third component that makes an oscillator an operator to review. One is routing to his discreet amplitude envelopes. Three is course tuning, and the fourth and final variable that might not seem quite is critical at first. But with advanced orm or intermediate level FM programming is gonna actually matter quite a bit. Is ah, velocity sensitivity per operator. So in here you have velocity to envelope, time or velocity to overall amplitude. This gives us the ability to essentially incorporate some keyboard articulation control to the way RFM patches actually sound as their played by a musician on the keyboard or ourselves or whoever. So now, now that we know a little bit about what makes on FM synthesizer what it is, let's take a closer look at how FM actually works. Here's r sine wave again. I'm gonna give it full sustained. Now, what I'm gonna do is I'm gonna add vibrato. This is classic vibrato. I like to do this one demonstrating FM because FM is frequency modulation. We're about to modulate the frequency right now, but just really slowly thistles, frequency modulation. But it's LFO frequency modulation, meaning low frequency. Watch what happens to this When I start to speed it up, There's kind of a threshold that gets crossed where it no longer sounds like individual cycles and even no longer looks like an individual peak moving back and forth. It starts to look like you can even see. When I lock my Acela scope up, you can watch the frequency slowly changing more rapidly. You essentially is called. This is a fan, but this is called Linear FM. This is more of like an old school analog way to do it. Just cranking your LFO way up. Watch. I can put this in the high speed mode. I've got FM coming from my LFO, but it's linear FM. Why is it linear? Because this LFO is not key tracking on a course tuning ratio. This LFO does not have its own discreet envelope normally, even though it actually does because this is a beautiful instrument, they add that on there. But this also doesn't have necessarily its own velocity sensitivity to amplitude, which again we need. And finally, we can't necessarily just route this out and make it an audio oscillator. It's on Leah Modulation generator. So remember the routing allows us to flip. Are oscillators from carriers to modulators. Here's all carriers. There's three modulators in one carrier. You can't do that stuff. So this is audio rate modulation on a really crude level also known as Linear FM. Remember what that sounds like? A mule watch This oh, starts to sound like a bell almost. But listen, when I play a scale, listen, when I play a scale, it's gonna sound dissonant. The way beating is different. Oh, dissonant, that is. That's because the rate of this LFO is not key tracked. It's not following our fundamental pitch. Whereas these, of course, are. These are audio oscillators. Let's listen to that same phenomena. But coming from a modulator that is key tracked with its own envelope, etcetera. Uh huh, constant all the way operate. So now this is RFM depth. Listen, when I change, my envelope is where things get really cool. Thing is now becoming an already classic sound. So FM it's audio rate modulation coming from our modulators modulators being operators that you can't hear, they're just providing audio rate modulation at a course, tuning math with their own envelopes and velocity sensitivity to the fundamental pitch of the carrier that is FM synthesis. So now time to move on to the second part of this lesson, which is okay. Now that I understand the concept, how do I make cool sounds with this? Here's my advice in general. First of all, if you want to make cool sounds with FM, stay away from the classic components of subtracted synthesis. Stay away from saw waves and square waves on Lee work with sine waves. The original Afghan instruments were only sine waves. And frankly, while you're learning how FM works, you're gonna get way better results. If you just stick with sine waves and, uh, versus just grabbing a square wave or assault wave, it's totally rich with harmonics. Um, so stick with sine waves. The next thing you really want to do is stay away from filters. As soon as you're over here grabbing a square wave on putting a low pass filter on there, it's a subtracted pretty close to just a subtracted patch. But listen when instead knowing that this is tone oops, get myself back over to sine wave essentially my tone control right here So let's go back to envelope. Give this thing full sustained. And now I'm gonna show you a couple of cool patches. First of all, what I like to do commonly, especially for making something I want to be thick, like a base patch or even a big, thick lead. So I keep my carrier always on one with fine tuning at zero, and I give it full sustain. This is like having a compressor on the track. So I just keep that sustained all the way up. I go to the second module or the first order modulator, and I kick it down 2.5. This is now going to give me a more thick FM vibe. Listen to what it sounds like without it. Wow. Versus 0.5. Whoa. I love that s so I'm gonna keep that, um, keep that rock in the way it is. The next thing I'm gonna dio was at another modulator, but this one's gonna have more of a plucky attack. This is if I'm going for more of a slap bass kind of sound. And I keep the tuning up by a little higher five or seven. And now we're getting into like Seinfeld territory right second out, it's gonna punch a couple notes in here. It did Watch this go this second modulator and I've got velocity sensitivity already turned up quite a bit. Watch this now and now we're getting into a funk his own here because we've got velocity articulation affecting our overall Tambor. This is great. Let's have another one up here. Let's go away. A stratosphere mode. Thats 12 I want lots of elastic sense, Teoh. Now that we have this thing rocking, let's try some other modulation combinations. How about this one carrier and three parallel modulators and three carriers one modulator global modulator, pure Syria's. So there's a lot of other tricks under the hood here, like oscillator feedback cross fading, your oscillators adding additional stereo image, adding distortion. These are all fun things to consider when you're making an FM patch. But for now I feel like we got a pretty good start sticking with sine wave, staying away from the filter, staying in pure Siri's another way to make sure you're really taking full advantage of FM. But don't be afraid to tinker around. These other modulation are other modulation configurations. Also, don't forget. Right below this, you've got a really nice key tracking section. This is going to go a long way. For instance, after touch is a really popular one, especially for push users. I love routing this one out to FM depth. So now all of these modulators depths are being controlled by how hard I'm holding my pads down. Another really cool one you can modulate is the drive of your distortion. Or maybe you're oscillator feedback oscillator. Feedback is only gonna be pertinent to the very final modulator in the chain. But here's our feedback since we've got such a people, Aaron Patch years not really providing us with too much. But you can totally control all of this with this nice school at Global the modulation panel. So we're all good things to keep mind as we're going to know how FM synthesis works. And, um, remember, this is just one quick lesson on FM. We have a six month long sound design program at Slam Academy, which is fully comprehensive, and everyone who leaves not only is a master of subtracted and FM synthesis, but also wave table synthesis, granular synthesis, physical modelling synthesis and all the other high tech language is that are required in creating cutting edge Elektronik sounds and music. So all right, this is James Patrick. It's been really fun, and that is the end of Lesson three for Class one. I look forward to seeing you guys in the upcoming classes.