Pure Data Patch from Scratch: Simple FM Synthesis Sequencer

A quick and easy Pure Data patch-from-scratch tutorial building a sequencer that plays dynamically changing timbres for each note though frequency modulation synthesis.

In this patch, we set up a simple sequence of sine wave pitches (frequencies), then a sequence of modulation frequencies of a different length, then a random patterns of deviations, creating a constantly changing series of sounds.

There’s no talking on this one, just building the patch, and listening to it go.

0:00 Sequencing the pitch of a sine wave
1:23 Creating modulation oscillator sequence
2:45 Randomizing the deviation
3:15 Audio math: modulator frequency
3:51 Audio math: deviation
4:09 Audio math: FM synthesis
4:31 Tweaking the numbers
4:52 Commenting the code
5:47 Adding delay (as usual)
6:55 Feedback for the delay
7:17 Listening and more tweaking numbers

More no-talking Pure Data jams and patch-from-scratch videos here:

Synthesis, Cybernetics, and Feedback

In my recent explorations of analog synthesis (as a former dyed-in-the-wool digital synthesist), I’ve found that feedback loops are one of the things that particularly different to explore in analog.

Inspired by the YouTube channel, La Synthèse Humaine, I’ve been doing a lot of feedback patches in Eurorack, with no-input mixing, FX pedals, and even digitally in Pure Data.

Better explained on the La Synthèse Humaine channel, “cybernetics” here follows Norbert Wiener’s definition: “control and communication in the animal and the machine,” since these audio feedback systems are “self-regulating” (self-controling?) sonic ecosystems.

Anyway, I’ve put together a playlist of my improvisations, collaborations, and ramblings about feedback and cybernetic systems. Enjoy!

Reaktor 6 Primary Resonant EQ (Faking the Serge Resonant EQ in Reaktor)

Building a resonant EQ in Reaktor Primary, taking inspiration from the Serge Resonant EQ’s unevenly-spaced frequencies and nonlinear controls.

In my regular journeys across the internet, I came across the Random*Source Serge Resonant EQ, a reissue of the resonant EQ from the Serge Synthesizer, and became a bit taken with its implementation and ideas. $400 is a bit too much for an impulse buy, so let’s see what we can do in Reaktor.

Random*Source Serge Resonant EQ

Even if we don’t end up with something that sounds perfect, we can use this as an opportunity to think more about subtractive synthesis, and talk about “parametric support” in our control schemes.

0:00 Purchase Your Way to Music Proficiency!
0:43 Random*Source Serge Resonant EQ
1:14 What’s interesting about this?
2:59 Disclaimer
3:22 Reaktor Primary Peak EQ
5:00 “Boost” vs. “Resonance”
5:53 Making Selectable Sound Sources
8:18 Throwing in an Oscilloscope
8:49 Starting the Resonant EQ Macro
9:28 Creating a Single Band
11:24 Level Controls to Avoid Clipping
13:13 One Knob for Resonance and Boost
14:28 “Funny Math”
21:13 Recapping the Flow / Fine Tuning
22:49 Duplicate! (for each frequency)
23:23 Setting the Frequencies
25:09 Adding a ByPass Switch
25:53 Sound Test
27:14 Saturator
28:04 Waveform Variance Across Instrument Range
29:38 Feedback
35:30 Next Steps

Are There Just 5 Types of Synthesis?

You can find a lot of lists out there on “Synthesis Techniques You Must Know!” These can be pretty compelling, but it can be helpful to take a broader look, and simplify synthesis into 5 big categories:

-Playback and Manipulation of Recorded Audio (Sampling and WT Synthesis)
-Additive Synthesis
-Subtractive Synthesis
-Distortion Synthesis and Modulation Synthesis, and
-Physical-Modeling Synthesis

By zooming out and thinking about these larger ideas, we make synthesis more accessible to people who are starting out, and we give a framework for people who are innovating new synthesis techniques.

0:00 Synthesis isn’t that complicated.
1:03 Five Categories for Synthesis Techniques
1:33 Playback and Manipulation of Recorded Audio
2:34 Additive Synthesis
2:52 Subtractive Synthesis
3:20 Distortion Synthesis (Modulation Synthesis)
4:08 Physical Modeling Synthesis
4:25 So What? / Hybrid Synthesis

More on fundamentals of synthesis here.

Internet-Based Feedback Loops: Eurorack vs. Zoom (with Spectral Evolver)

Using the latency from videoconferencing software as a delay for Eurorack feedback loops, creating (noisy) evolving sonic textures.

I’m in Connecticut, Spectral Evolver  is in Colorado, but that doesn’t mean we can’t connect our Eurorack systems.

Through the “magic” of Zoom, we create a feedback loop: I’m ring modulating the signal coming in from Zoom, he’s filtering the signal coming in on his end. This creates a “no-input” system across the world wide web, allowing us to create evolving textures inspired by Dutch composer Jaap Vink.

More on feedback loops and cybernetic systems here:

Making a “Subharmonicon” in Reaktor

Building a subharmonic synthesizer in Native Instruments’ Reaktor 6 Primary inspired by instruments like the Mixtur-Trautonium and Moog Subharmonicon.

Subharmonics are frequencies that are whole-number divisions of a given frequency (in contrast to harmonics, which are whole number multiples of a frequency). While harmonics naturally occur as part of the timbre of a sound, subharmonics, when introduced, sound like distinct pitches, allowing you to create chords of harmonically-related notes.

This tutorial walks you through making a set of subharmonic oscillators and envelope filter like the ones on the Moog Subharmonicon.

Moog Subharmonicon

More on harmonics and additive synthesis here.

Pd Patch from Scratch: Ring Modulation and Filterbank

A quick and easy Pure Data patch-from-scratch tutorial building another feedback loop with a delay and a ring modulator, this time with a fixed filter bank.

Inspired by the music of Jaap Vink, with three sine waves, a filterbank, a delay, and some feedback, we can make some slow evolving-complex and dynamic sounds.

In this patch we take a sine wave, ring modulate it, then ring modulate that result before running into a filterbank, delay, and then feeding it back on itself.

There’s no talking on this one, just building the patch, and listening to it go.

More feedback loops (in analog):

Understanding Granular Synthesis

Explaining granular synthesis and giving demonstrations with the Kyma GrainCloud and SampleCloud sound objects.

Granular synthesis is a synthesis technique where we can assemble new sounds from very short “grains” of sound. We can do this with wavetables or longer samples, breaking them down into these short grains before reconstituting them back together in unique ways. Because we can change all of these tiny parts that make up our new sounds, there are exciting opportunities for real time control and performance.

What’s Happening When Audio “Clips”? (Hard Clipping, Soft Clipping, & Harmonics)

Diving into “clipping” in audio, and thinking about the aesthetic possibilities of going beyond the limits of a system.

In this video, I use Audacity and Max/MSP to look at examples of both hard clipping and soft clipping, checking out the harmonic spectra of these distortions and thinking about how we can use clipping as an expressive tool in our compositions or sound design.