Anatomy of a Patch: Kick Drum in Sylenth1
The process of making synthsized drum samples from scratch is simple but often overlooked. We start an exploration of how to do it here.
by Vincenzo Bellanova, Nov. 2017
Drum synthesis – what a wonderful world! The process of making drum samples from scratch, starting from synths, is simple but often overlooked. In fact, you may have noticed that tutorials on the net aren’t that precise, or, to be more analytic, people tend more often to rely on ready to use sample packs. It is an “ancient” and long discussed topic: to make all the sounds on your own or to use external material. Before starting, we would love to point out that this is a matter of choice, sometimes we do not have all the time to synthesise or record everything we need, or simply we leave these works to the sound designers, as composers may focus on their main goal, compositions. Different choices.
Drum synthesis is precision, sometimes surgical, but it leans on the usual tools we already know (and probably own), so it’s just a matter of practice!
In our series “Anatomy of a Patch” we will deconstruct some patches and we will analyze them, in order to understand every single nuance of the sound we will purpose. We will also give tips and advices on how to make variations and we will suggest other tools or techniques.
In this installment we are going to make a Kick Drum in Sylenth1, a subtractive synth by Lennar Digital that gained a lot of attention during the past years. We will only use functions that are commonly shared by every subtractive synth on the market, so don’t worry, following these steps you can easily achieve the same result with other soft synths!
For this sound we will need two oscillators, each with its own independent envelopes for pitch and amplitude (sorry, Diva fans, you’ll have to skip this one). We will not need any filtering (an usual state of things for a subtractive synth patch).
Our sound will consist of two layers which we can think of as the body and the transient components of the sound. The duration of the transient is much less than that of the body. However, as you’ll see, the body component has some pretty fast pitch action happening within it. We will use the first oscillator for the body and the second for the transient.
Kick Drums are usually made of a sine wave with an envelope on its pitch. The ultra quick pitch excursion will result in a sharp top, that falls down into a deep body, corresponding to the sine wave’s main pitch (the value we set initially).
It is important that we monitor the fundamental frequency of our kick from the beginning. That frequency should be (generally, it depends on the taste and on the genre) between 40 and 50 Hz.
For finishing, we can choose to add distortion and compression, EQ, but at the core we will have a sine wave with its pitch and amp envelopes for both the body and the transient.
First off, let’s initialize our preset (CTRL + J is the shortcut for Sylenth1) and put a spectrum analyzer on your channel. We are using Ableton’ Stock EQ Eight, but you can choose any other spectrum analyzer (Voxengo SPAN, for instance, is a great one and it is free). Select the sine wave for your first oscillator and create a MIDI clip with a note, so we can hear and monitor our fundamental frequency.
Be sure your fundamental hits the recommended zone, you can adjust the note of your MIDI file or the pitch of the oscillator (in this case we lowered it by one octave).
Another point that requires maximum attention, is the Retrig function. Retrig means that every time we hit a note (either on the keyboard or with a MIDI clip) the waveform starts its cycle from the beginning, while if this function is not active, our sine wave will play with an unpredictable phase offset. Why is this so important? When we raise the voices of the oscillator to eight (the maximum on Sylenth1, in order to have a more consistent volume), we want our oscillator to sound identically for every hit. Without the retrig, we would have a different sound every time.
Now, using more than one oscillator voice is sometimes known as unison. Use of unison is also usually accompanied by the practice of slightly detuning the oscillators for a richer sound. However, here we use multiple oscillators without detuning just to get more “oomph” into the sound. We can think to the unison as multiple intances of an oscillator, and this, multiplied with the voices of polyphony, i.e., the maximum number of notes we can write on our MIDI file or press on a keyboard, will result in the maximum number of voices of the synth.
We almost have our body, but our sine wave will play as long as our MIDI files goes, so we need to trim the Amp Envelope to get closer to the Kick shape. Turn the sustain down to 0, and just play with the decay to taste. A little tip: to avoid a “click” at the end of your sound, raise the release a tiny bit: the amplitude of a waveform moves up and down around a center line, the zero point, reaching its peaks at +1 and -1: if the waveform does not end on this zero point, we will always hear that “click”. The audio clip just below illustrates what we’ve done so far (you may need to turn up the volume to hear it properly).
Let’s move now to the modulation section, on the bottom of the interface. Now we are going to assign the Modulation Envelope to the Part A pitch, by clicking on the first light blue slot at the right of the little knob, and select “Pitch A” from the menu. We are going to select just the Part A because we will treat the Part B differently for our top.
While the Amp Envelope controls the volume of the whole synth, with the modulation we are going to move a parameter of our choice: the parameter we are going to move is called the destination, while what is going to move our parameter is called the source. There are a lot of different sources for modulation, the most common are Envelopes and LFOs. An envelope is going to “automatically” move our pitch (in this case), think to the course of the pitch moved up or down, following the time and shape of the modulation envelope.
As for the Amp Envelope, we won’t need any sustain, let’s play with the decay instead. Which decay which we will set to 0.727. With the pitich envelope, however, we’ll need a super short decay time, because the rise of the pitch needs to be very fast to achieve that “top” or “zap” sound. We used a value of 0.545 (you can check the numeric value of the parameter on the main central window) for the decay.
However, we need to face another key concept in order to understand how modulation works: the Depth. You can think of the depth as the amount of modulation: in this case, how much the pitch is going up or down. It is controlled by the little knob right under the Attack fader in the Mod Env section, and this control is bipolar: this means you can set either a positive value or a negative value (in case you want the pitch to fall down). We set our knob to 1.200, not that audible as effect, but, as we said, this section (the Part A) is going to be just the body of the sound.
Now that we have our body, let’s think to the top of our Kick drum, i.e., the transient part of the sound as opposed to the main body. This is going to be easy, because we just need to make the same as Part A, but with some adjustments, in Part B.
We will need another sine wav for Oscillator B1, this time raise the unison voices to six, this will result in a quieter sound. Here we will leave the main pitch unaltered (recall that we pitched down the sine wave of the part A by One Octave) because we need the transient, or top, to sound higher than the body. The Amp Envelope will have the same settings as the Part A, except for the decay which we had set it to 0.727, a super short envelope, because the Part B will be just the transient of our kick.
Again, let’s assign the Mod Env to the pitch of this oscillator. This time, the modulation will be more aggressive. Let’s set a decay of 0.273 and a modulation depth of 7.600. In other words, the pitch will be higher, and will fall quicker, resulting in a sort of “click”, right what we need for our transient.
Now that everything is set, let’s play with the volumes: in the right part of the synth, you can balance between Part A and B. We lowered the volume of the top and raised the main volume of the synth.
Here’s our kick drum! Follow the next step for some tips on how to mix it and refine it with compression and distortion!
Here we are with the final refinemenst and general tips on how to finalize your kick.
We added some distortion, foldback in this case, a type of distortion that takes the part of the waveform that is clipping, and mirrors it down, resulting in an alteration of the original sound adding harmonics. The distortion is set to 100% Wet and just a tiny bit of amount, in order to boost the sound a bit. Distortion is always a good idea in our opinion, when used correctly. It simply adds harmonics, making your sound richer. We recommend to try it before an EQ, because distortion is an additive process, so adding harmonics, will probably add something you don’t really need, and an EQ can help you to polish your sound. Try different algorythims and plugins, each one sounds different! We recommend iZotope Thrash 2 with its huge library of algorythms, or FabFilter Saturn, a multiband Saturation Tool.
Then we added a low pass filter in the Part A, with the cutoff to its maximum, so it is not cutting frequencies actually, but activating the filter allows us to use the drive control, a saturator that enriches the filter behaviour, really on point for the body, and, in general, a great feature of Sylenth1.
Lastly, we added some compression to tighten all the sound a bit.
You can also try to layer your body with other tops, or vice versa. Sometimes organic tops, like poppy percussions or short snappy transients, work reeally well. Try with a closed hi hat too: deactivate the snap to grid, and put it some milliseconds before your kick sound!
Some other finishing touches could be applied using very moderate random modulation amounts so that successive occurances of the sound (a given with a kick patch) don’t sound identical. Using just a touch of randomness on the pitch envelop depth, decay (and release) times are particularly attractive targets. But keep it very light. A little of this sort of thing can go a long ways.