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 Synth├Ęse 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 Synth├Ęse 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.