Synthesising drums is surprisingly easy once you have the know how and the experience. You can create amazing drum sounds on pretty much any synthesizer, however the synth of reference today is XFER Serum.
Envelopes
The first and most important step for synthesising drums is shaping the amplitude envelope. Especially when making percussive sounds, it is important to get the shape of the envelope correct otherwise your drums won’t sound like drums.
The ADSR envelope is the most common way to modulate certain parameters of your synth. A stands for attack, D stands for delay, S stands for sustain, and R stands for release. This sculpts the sounds you are making. The ADSR envelope most commonly modulates the amplitude of the sound, or the frequency of the filter.
The second option is the LFO, this stands for low frequency oscillator. The LFO is just like the main oscillator of your synth that produces the noise except it runs at such a low frequency it is inaudible 99.99% of the time. They play the wave at a lower frequency than human hearing can hear and are usually assigned to a parameter of the synth to modulate it.
Personally when I make drums, I like to use the LFO as it is much more manipulatable on my choice of synth (serum) however on different synths especially analogue ones you will need to use the ADSR envelope.
Waveforms
Once you have your envelope, the next thing you have to choose is the waveform that you will be using for the drum.
A sine wave is a wave which is just a pure tone with no other harmonics
Triangle waves are waves with a exponentially descending harmonics creating a warm/fuzzy sounding wave (Moog Percussion Guide)
Square waves have only odd harmonics which creates a very hollow sound (MPG)
Saw waves are made up of integer harmonics (an integer is a whole number) they have a very bright sound useful for making warm and articulate percussion (MPG)
Noise contains all frequencies and harmonics which is very useful when creating snare drums, cymbals, and just generally adding an acoustic element to your percussion sounds.
Kick Drum Synthesis
The first drum I would think of when it comes to drum synthesis is the kick drum. As far as synthesis is concerned, making a kick I do is very easy. I synthesise all of my drums in serum.
The first step when synthesising a kick is to get the base wave – the main body of the kick. For this you can use a filtered square wave, or a sine wave as they work best. After this you want to create an envelope for the base of the kick drum, make it a 1/4 beat of the bpm of the project that you are working in and make it in a shark-fin shape.
Once you have the base of the kick, you next want to make the main transient which will be a pitch bend of the wave. Make it short and sharp and pitch the wave down about 11 semitones to get the best effect of a thump. Once you have done this create a second envelope and make it even shorter and play around with the pitch bend for your desired effect.
You may also add a noise transient and additional filter sweeps to create more variation in sound.
The final process is to add some effects to your kick drum, eq’ing and mild distortion are what I prefer and I usually modulate the effects to one of the kick transient envelopes.
(G.Reid)
Cymbal Synthesis
Creating cymbal sounds is a lot more varied than creating the kick drum.
The main thing you use to create a cymbal sound is noise. With noise you can use various envelopes, short for hi hats and long for crashes, to modulate the sound as well as effects to further change the sound.
For Hi Hats there are 2 types in my personal view, swooshy hi hats and clicky hi hats.
To make a swooshy one you first want to use a sharkfin envelope on the volume parameter of your noise. After that apply some asymmetrical distortion and an eq cutting the low end off and you have a very simple swoosh hat.
To make a clicky one, take your noise and give it a very short and sharp envelope. After that you want to apply a bandpass filter with the drive and resonance turned right up and set the cutoff to 3K or above. Finish it off with some distortion and you have a clicky hi hat.
The best way to create good long cymbal sounds is FM synthesis.
https://www.soundonsound.com/techniques/synthesizing-realistic-cymbals
Here I have attached a very good guide into how you use FM synthesis to create cymbals. In short you modulate the FM amount to your personal desire and shape the sound from there.
Snare Drum Synthesis
Synthesising snare drums is complicated.
The first step is the transient at the start of the drum. The best way to achieve the sound of the snappy transient is to use a sine or filtered square wave with a very sharp pitch bend and a very short volume envelope.
Next you want to make the main body of the sound. To do this you want a noise wave with a sharp shark-fin envelope. This combined with the very quick transient will already start sounding like a snare drum.
Once you have the two oscillators set up, you next want to apply a band pass filter to the sound and push the drive all the way up. You can also tweak the parameters of the filter to achieve your desired effect. After you’ve filtered it, it should already be sounding great and like a snare drum.
Once you have a sound that you like, apply distortion of any kind, different distortions have different sounds, and eq the sound taking the low end out and creating a small bell where the fundamental frequency of the snare roughly is.
Clap Synthesis
Claps are probably my favourite drum to synthesise because of the endless ways you can make a clap.
The sound of a clap lies in 3 important steps – the noise texture used, the lfo shape, and the filtering.
First for the noise texture you have a couple options. You can either use a sample of noise, you have many different ones built into serum, or you create your own texture using the wave tables and synth modulation (FM with fast lfo)
Once you have the noise sample you want to use you then create the clap transient and envelope. This is an lfo with a few jagged spikes at the start and then a longer section and finally a release at the end of the envelope, very simple but once you apply this lfo to the volume parameter and tweak the speed to your liking you will already have a sound which sounds very much like a clap.
After this all you need to do is band pass it and tweak the parameters to your liking, add effects like distortion and you are done.
References
Reid, G. (2002) Practical bass drum synthesis, Practical Bass Drum Synthesis. Available at: https://www.soundonsound.com/techniques/practical-bass-drum-synthesis?amp (Accessed: 04 March 2024)