 Hello, Oscillator Sync here. Today I want to talk to you about envelopes and introduce what I consider to be the three essential envelope recipes that every synthesisist should know. But first, some background. In synthesis, envelopes are, along with LFOs, one of the two main modulation sources that are common to most synthesizers. Modulation source sounds like a scary techie concept, but it's really just a posh way of saying something that moves the knobs and sliders on my synth for me. In the case of an LFO, it moves the knobs and sliders up and down cyclically. It's where we get our pitch vibrato, our volume tremolo, and most importantly, our wub wubs from. Envelopes are a little more interesting in my opinion. They take your synths and knobs and sliders on a journey that starts when you play a note and comes to an end as you release the note. More generally, we might talk about envelopes as describing the shape of sounds over the course of a note being played. Whether that's the shape of its loudness, its frequency content or timbre, or maybe even its pitch. I think this idea of the shape of a sound over time is sometimes easiest to consider with acoustic instruments. Take a listen to this piano note. It has this strong percussive attack followed by that long lingering decay down towards silence. If we take a look at the waveform for the sound and trace the shape of its amplitude or loudness, we can see the envelope that represents that idea. It gets loud almost instantly, drops down to a lower volume pretty quickly, and then takes a much gentler descent down towards silence. Interestingly, if we take the same analytical approach with a tom drum, we can see that although piano and a drum make quite different sounds, their volume envelopes are actually pretty similar, which makes sense. After all, they both share the property of fundamentally being percussion instruments. If we contrast this with a violin beam bowed, we can hear and describe by way of its envelope a sound which eases its way into being and actually holds itself at a much more steady volume while it sustains. Coming back to synthesis, if we wanted to emulate these kinds of sounds with our synthesizers, we would want to set up our volume envelope, so on an analog synth, for example, that would be our VCA envelope, to match the shape of the envelopes we've been taking a look at. But let's take a minute to think about what setting up an envelope means on a synth. Envelopes on synthesizers come in many forms. These range from the simple two-part attack and decay envelopes like we see on the Korg Monologue, up to the complex multi-stage envelopes that we find on the DX-style FM synths. There are even these eight stage behemoths that you find on the old Casio CZ series. I mean, look at this thing. Leaving those aside, far and away the most common form of envelope that we see on synths is the trusty ADSR envelope. Let's just talk briefly about what ADSR represents. A is for attack, and it's the time taken after a note begins for the envelope to go from zero up to its highest point. Because we're talking about time taken here, a low attack value means that the envelope jumps up very quickly, whereas a high attack value makes the envelope ease in slowly over a longer period of time. It's best to consider the next two stages, D and S, together. D is for decay, and it represents the time taken once we've got to the highest peak for the envelope to drop down to the level defined by S, which stands for sustain. Again, we're talking about time taken, so a low decay value means that we take a short amount of time to drop down to the sustain level, whereas a high value means we drift down more slowly. The envelope then sits at the sustain level for as long as we continue to play our note. When we stop playing a note, the final stage of our envelope comes into play, R, which stands for release. Release tells us how long the envelope will take to go from its current level back down to zero. A low release value means we take little time to plummet down, whereas a high release value means the journey takes longer. A quick note regarding the release, it kicks in the moment we stop playing the note, which means that the journey down starts from whatever point we're at in our envelope. So if we're still on our way up to the peak in our attack stage, we just abandon that climb and begin the descent from wherever we've gotten to. So with that out of the way, let's get back to the three essential envelope recipes. These are the envelope shapes that I come back to again and again when creating synth patches, and whether I use them in their basic form or modify and embellish them, they'll form at the very least a starting point for me. So let's meet them, shall we? The organ envelope is more notable for what it doesn't do than for what it does. I've talked a lot about envelopes letting us take our sounds on a journey, but there's no real journey here. This setting is more like a switch. Note, envelope turns on. Release the note, envelope turns on. To make an organ envelope with an ADSR, you want to set your attack and release to zero so that the sound starts and ends instantly and you're sustained to full. It doesn't matter how you set your decay, as with the sustain set to full, there's nowhere to decay to. Nevertheless, I usually set it moderately low so that if I change the sustain level later, it's more obvious. Despite its apparent boringness, the organ envelope is tremendously important. You most often want to make use of it with a volume envelope in situations when you want other modulations to do all the talking. Big funky bass or mono lead sounds that are defined by their filter sweeps or pulse width modulation benefit from an organ volume envelope so that none of the filter womp or squonk is lost to the sound fading in or out. In terms of variations, I don't want to stray too far from the basic shape or end up with one of our other recipes, but the obvious tweak is to soften the attack and or release by turning them up just a touch. Even with very small adjustments, this can actually help define the overall character of the sound in quite a nice way. The onset of the note still sounds, for all intents and purposes, instant, but a very slightly longer attack and release can make the patch sound softer and more chilled and might help a synth with a very quick envelope sound a little more vintage in some cases. It's also a nice variation if you start to hear clicking at the start or end of the sound, which some synths sometimes suffer with, especially on very low notes. The pluck envelope is my go-to for sounds which require a percussive or punchy attack. It's a tremendously versatile envelope which finds its home in many different styles of patches and works while modulating a wide range of parameters. Volume, filter cutoff, pulse width, pitch and more can sound awesome under the control of this envelope setting. With an ADSR, a basic pluck envelope is defined by setting our attack to zero, having a fast decay and a sustain set somewhere below max. How we set our release is a little more up for exploration, but as a good safe starting point, I set it to be at least as long as we set our decay so that the envelope reacts in a natural way whether the patch is played staccato or legato. If we look at the shape that we've defined here, it's hopefully going to look a little familiar as it's pretty similar to the envelope that we saw when we were looking at the piano and tom samples, both of which shared this punchy, plucky attack. We can modify how sharp the attack sounds by playing with the decay and sustain values. As a rule, lower and therefore faster decay settings coupled with lower sustain levels will provide sharper sounds. Slower decays and having less of a drop using a higher sustain level can still sound plucky, but it tends to have a rounder, tubbier feel. As I mentioned, the pluck envelope works great with more than just volume. Filter cutoff and pulse width both make fun modulation destinations and you can highlight their effect by using an organ envelope on the volume. Sending a pluck to pitch can really bring out the percussive nature of the sound, and this idea forms the basis for a lot of synth drum sounds. Just remember to drop the sustain down to zero if you want the pluck to land on your note's original pitch. Although pad patches come in many shapes and sizes, the classic arctype is that long, languid patch that fades into existence, evolves slowly over time and then bids us a lingering goodbye. And the basis for this sound is an envelope that is all about long, gentle movements. We start by setting our attack, decay and release to suitably large values and our sustain to a moderate level and then just sit back and enjoy the ride. Of course it's not just the volume envelope that enjoys this treatment. Any parameter that affects the timbre of the sound such as filter cutoff or pulse width is a fantastic choice too. Do remember though that if you want your patch to be all about this timbre movement then it's often beneficial to ensure that your volume envelope opens up early enough for everyone to enjoy it. And you can do this by lowering the volume envelope's attack time, maybe even to the point of immediacy. In terms of variations to the pad recipe, one neat trick that you can use to add drama to a patch of this type is to use a combination of a shorter decay and a lower sustain. This arrangement means that after the initial long climb in the attack phase you swoop down suddenly subverting the expectation of a gentle ride that your attack set up. Taking that idea to the extreme and setting your decay and sustain to zero provides you with a faux reverse effect that can work really well once you fine tune the attack time to match the tempo of a song. I hope that whether you arrived at this video as a synth newbie or came along hoping to find inspiration for some new sounds that you've taken something useful away. If you did find the video useful then please give it the old thumbs up, share it with your fellow synth enthusiasts and make sure you subscribe to the channel so that you don't miss out on any upcoming synth related fun. As always, thank you so much for watching everyone. Take care and I'll see you again soon. Bye bye.