 So we want to learn how the sound synthesizers work so we can make your own sounds. Awesome! In this video, I'm going to show you all the basic concepts and demonstrate to you how synthesizers work and how you can manipulate them to create your own sounds. Hey, I'm Anfa. I'm an electronic music producer and sound designer, but I only use open-source software and Linux. Synthesizers are made up of modules and each module does a specific thing to the sound signal. For example, it generates a steady tone or it changes the volume of that tone or it removes some frequency content. There are basically two kinds of synthesizers. There are modular synthesizers where you're given all these modules like Lego bricks and you put them together however you want and there are non-modular or semi-modular synthesizers where the blocks are already put together in a sensible configuration for you and you have limited freedom to put them how you want. It is of course limiting but it also makes working with a synthesizer that is well designed much faster and easier. The synthesizer I will be using in this tutorial is called Vitalium and it's an open-source version of the Vital synthesizer created by Matt Tytel. Vitalium is a very powerful wavetable synthesizer but I think it's also a great tool to showcase all the basic principles and once you have a cad start using this instrument, the sky is the limit for your sound designing adventures. All right, so let's start with the first building block which is an oscillator. An oscillator is a module that generates a steady tone. For example, this is how a synthesizer sounds where all it does is uses a oscillator with a sawtooth waveform. You can see that the oscillator module is right here, this panel. It's called OSC1 for oscillator 1 and we have a sawtooth waveform. Classic oscillators can generate a few basic types of waveforms and these are the sawtooth, the square wave, the triangle wave, and the sine wave. Now I'm going to explain also what all these sound analyzers do all around. So let me play a basic tone. This is a sine wave. It's the simplest possible sound. It's a single pure tone which means it's a single frequency. You can see that on the oscilloscope view right here we are seeing the same sine wave shape. If we were to look closely at a diaphragm of a speaker producing this sound it would move exactly in this pattern. This is why we call this a time domain display because it shows us where a speaker membrane would be placed in relation to time. Let me change this to a saw wave. You can see that this shape I have here looks a bit different than this one. So actually it's just that we are looking at a different part of the same waveform. You can also see that we have much more things going on on top. So I'm going to tell you what these scopes do. In the top right I have a spectrum analyzer. It shows us individual frequency peaks and their power. So on the left we have lower frequencies. On the right we have higher frequencies. If I play a higher note you can see that higher notes start in the right part and the lower notes start in the left part. So here we have our time domain display and here we have our frequency domain display. That means we're not watching the function of motion of the speaker's diaphragm. We're watching the sound broken down into individual pure tones because as you probably know every complex tone can be broken down into pure tones. That is sine waves and this is exactly what this spectrum analyzer does. It shows us what sine wave frequencies we would have to use to reproduce this sound that we're hearing. Now let me talk about this wider display here. This one does the same thing as the spectrum view but it's called a spectrogram. And what it does is it plots the spectrum in relation to time so we can see the history of our sound changing. So you can see I can see a bunch of notes being played in the past and the spectrum the spectrogram is scrolling upwards. This is very useful in sound design to understand how your sound is changing in time and it's much more useful than watching a waveform. However I have all of these free displays to help you understand what are you hearing when we're going to be going over these basic synthesizer operations tools and produce various sounds. All right so let me show you how the basic waveforms differ. This is a salt of wave and a salt of wave is defined by that it has every single harmonic. Let me switch to a square wave. You can see that the square wave has every other harmonic while the salt wave has all the harmonics. And this is a very important difference. The waveforms provide us with raw material. It's like a block of rock or wood that we're going to sculpt our sound from removing certain parts to create interesting shapes. A raw salt of wave or a raw square wave isn't very interesting but it still can be used effectively and still in modern electronic music and not just electronic music. These very basic waveforms are still used with great success. You can see that the triangle wave has all the same harmonics as the square wave but they drop off much more quickly. So you can see our harmonics in the square wave are decaying pretty slowly and the triangle wave they're decaying much faster. Also we can ignore these tiny harmonics here. I think this might be some harmonic distortion. All right so I hope now you understand what these scopes do and we're going to move further. So we've got the oscillator. The oscillator produces a steady tone and in the paradigm of subtractive synthesis this is how we go. We get a harmonically rich raw waveform and then we use a filter, another module, to remove part of the harmonics or part of the frequency spectrum to shape our sound into something more interesting. So let's enable a filter module. Right here we have a filter. Let me play the sound again. Let's turn it off and on. You can see that we created something that sounds more like the triangle wave that we saw before. Both here and here maybe not that well but pretty close. So this is a filter. There's filters remove frequency content. If we change the cutoff frequency you can see that now we have our basic square wave back and as I sweep the filter down it's removing harmonics until we'll left with nothing but silence. There are also other types of filters. This is a low pass filter that means it removes the high frequencies and lets the low frequencies through but we can change it to a different type of a filter for example a high pass filter which will let through the high frequencies as the name suggests and there's also a band pass filter which removes the high and low frequencies and leaves us with the middle ones which might be a little bit hard to see so I'm going to play a lower note. You can see on the spectrogram that we are we have this little peak sliding up and down just as I move and this is our frequency peak of this filter. Now filters have various parameters besides just the cutoff frequency which is the thing I'm doing I'm changing right here. There is also the steepness of the filter and right now we're using a 12 decibels per octave filter. There's also a 24 decibels per octave filter which is twice as steep and you can see that our separation of what is passed through and what isn't is much stronger. We can clearly see this frequency band being sweeping up and down in here as well as on the frequency scope. Another parameter of a filter is resonance. Resonance creates a peak on the cutoff frequency so if I rise the resonance we're going to boost a narrow band of frequencies maybe we could change this type of filter for a cleaner one. Oh yeah this digital filter doesn't have this distortion that the analog one has so it's going to be better for demonstration. Now if we change this type of the filter to low pass again I think you're starting to recognize some very familiar sounds from electronic music. All right so that's filters. These things in themselves are not that interesting like if I want to play a melody now the sound is pretty boring. There's nothing going on in it. It's very static. So here come envelopes and LFOs. Envelopes or envelope generators are modules in the synthesizer that create control signals. You can think of them as units that grab other controls and move them for you. So for example we have this first envelope and it's being used as an amplitude envelope. That means it's controlling the amplitude of the sound. Right now it's not doing anything interesting it's just turning on and turning off immediately. But we can change that. For example if I lower this sustain value our sound is getting quieter as I'm holding the key. And then it's getting sustained at this value. When I release it it becomes silent again immediately. And this is the basic ADSR envelope model which means attack. Attack defines how slowly the volume rises. Zero attack means immediate. So if you're synthesizing drum sounds you're going to need zero attack. Sustain is how loud the note stays after you hold the key. So it's never going to be quieter than this unless I release the key. We can move it all the way down to zero which means the note will decay to zero even if I'm going to keep pressing the key. As you can see in the bottom here I'm still holding the key but it has decayed to silence. And there is also release. So if I move the sustain up a bit and make the release longer now I release my key but the sound is still taking some time to decay to zero or release. I can make this even longer now if I press a key I'm not pressing the keys but the sound is releasing for quite a while. So this is the amplitude envelope. Every synthesizer has an amplitude envelope because it's pretty crucial to control the loudness of the sound at any point in time. But the real thing is there is actually two things going on. We have the envelope generator module which controls the control voltage or control signals and there is the amplifier module which actually changes the loudness of the sound. But it's being controlled by this envelope. Let me reset this to something more or less default. And now we can use multiple envelope generators. So I'm going to switch to envelope two. And I'm going to assign it to the filter. Let's drag it on in here and release. Now I'm going to play it out. You can see that our filter cutoff is changing and probably it's too high so I'm going to double click to reset this to default. We have some interesting motion in the end because we have a release. So let me reduce the sustain value. Now that's interesting. This is called a filter sweep. And it's a very classic tool in sound design. This is pretty much everything you need to make acid music. Just add some distortion. We can also reverse this and instead of making the envelope decay with time we can make it rise up. So I'm going to move the sustain knob all the way up and move the attack knob up as well. There are many interesting things you can do with just an envelope and a filter. But let's move past that. I'm going to middle click on this assignment to temporarily disable it. I'm going to move this filter here and maybe make it more more neutral. I'm going to change this to a salt wave as well. All right. Let's now talk about LFOs. LFO stands for low frequency oscillator and that is another module in a synthesizer which creates cyclic waveforms but they are not meant to be heard directly. It's very much like the oscillator we have right here but LFO is generating oscillations which are lower than audible sounds that is lower than 20 oscillations per second. So I can click and drag our LFO onto this filter. If I lower the cutoff. The filter the LFO is creating an oscillating triangle waveform that is now controlling my filter cutoff. We can also make it a sine wave. And now we can change the frequency. By default in Vitalium the frequency of the LFOs is locked to project tempo. However we can change this if I click on this note to seconds. Now this may sound pretty familiar to people remembering early dubstep. This is pretty much all you need to make these classic wobbles. Maybe we can make this LFO do some more. There we go. So the LFO is now oscillating 10 times per second or with a period of 0.1 seconds and it's modulating our filter cutoff creating this wobble. Maybe let's make it go back to tempo and we can change between quarter notes, eighth notes, sixth notes. Okay using filters is all fine and dandy but we can try and do some other things as well. Let's disable the filter for now. I'm going to switch this to a triangle wave and play in a higher octave. Let's use this LFO to modulate a different attribute of our sound. Let's go with the oscillator volume or level. So I'm going to click and drag onto this level knob and it's getting a bit loud so I'm going to right click on this modulation widget. I'm going to make it bipolar. Now it goes up and down not just up. I'm also going to lower my bass level and increase the modulation amount. So now you can see our sound is pulsating. The LFO is controlling the volume of the sound. I can make this faster. This sounds like a sci-fi computer printing text on the screen, right? Maybe if we pull it even higher. I could be painful so sorry if it is. I'm going to go back to the lower notes or this could sound like a force field or like a spaceship. Okay let's disable this volume modulation. I'm going to middle click move it back up and now let's try and modulate pitch or oscillator frequency. I'm going to click and drag and drop it into here. That's intense. I'm going to lower the frequency to a half note and this is a pretty perfect um visualization because now we have this triangle wave and we have a triangle wave here and we can see both of these waves. Here our waveform is squishing back and forth stretching in and out as we're changing the frequency and here our spectrogram is drawing this shape of the triangle wave in the LFO. Maybe let's change this triangle wave to a sine wave so it's clear what's going on. Well this is a pretty strong effect but we can make this more subtle. Right now we're modulating it by four octaves up and down I believe. Let's do it by a semitone. Let me make it shorter faster. That sounds a little bit like a UFO from very old sci-fi movies doesn't it? So you can see that we can combine these modulation sources like envelopes and LFOs to create to affect various aspects of our sound inside a synthesizer to create very different sounds. We could combine all of these now and for example add a filter maybe use a different LFO so I'm going to mute our filter modulation by middle clicking. I'm going to use a different oh no I'm going to use the envelope. Oh because we are using a sine wave we don't have many harmonics to affect so our filter does nothing. I'm going to go back to a saw wave. We can also make our envelope sustain zero and then the sound would go up and down. There's a billion other things we can do especially in this synthesizer because it's a very powerful instrument but I'm going to show you just two more things so you don't get confused and overwhelmed for starters. Many synthesizers include some form of effects and effects are separate modules which do certain things. For example a reverb effect would simulate how the sound is bouncing off the walls in a room creating an illusion of space in the sound. A delay effect would repeat the sound with lowered volume to create an illusion of echo or the sound bouncing off a distant wall and we can use these effects to make our sounds a bit more interesting. Here is the effect section of vitalium and let me enable reverb. You can see we have these ghostly trails left behind our sound. If I make the time longer and the mix stronger you can see it's like our sound is being blurred and leaves traces. This is what reverb does. It simulates a lot of reflections of different surfaces which create these beautiful tails and give us an impression of space. We can make the reverb shorter and make it less strong or more strong. Let's also add this delay effect. Here it is. If I disable the reverb we can hear the delay on its own. So you can hear it's repeating the sound and lowering its volume with each repetition and they're both. So that's an eerie soundtrack for you. This is all I wanted to show you today. I hope this was an inspiring introduction to sound synthesis and I hope you have an understanding of what the basic elements of every synthesizer are and I hope this will encourage you to explore. You can get all the software I'm using. It's all open source software. I'm using Linux. If you would like some help with maybe trying out Linux or if you're running Linux help installing software and getting it to work please join my community chat at chat.anfa.xyz. There is also a Discord server and these two are bridged together but Discord is proprietary and this chat at chat.anfa.xyz is Rocket Chat which is open source and self-hosted so it's more secure and privacy respecting. So feel free to join that community and ask questions. Also feel free to explore my other videos and if you have any questions and things that you would like to see me cover in another videos please leave your comments in the comment section below. Of course I will link all the used software so you can download it for yourself and use it and that's it. Thanks for watching. I also want to thank all the fine people who are supporting my work financially. If you're the reviewer would like to join them please go to patreon.com slash anfa or liberapay.com slash anfa or you can give me a buck or two now go and synthesize some sounds I hope this synthesizer isn't overwhelming for new users but I think even when you can just disable modules and focus on different stuff maybe it's gonna be a good fit.