Pd Patch from Scratch: Filter Pinging

Doing some filter “pinging” use the resonant [bob~] filter in Pd Vanilla.

Filter pinging is a synthesis technique where you sent a “pop” (i.e. an audible click) to a resonant filter to create a percussive plucking sound around that filter’s cutoff frequency. Since we’re in Pd Vanilla, the easiest way to get a resonant filter is with [bob~], the “Runge-Kutte numerical simulation of the Moog analog resonant filter.”

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

0:00 Setting up the filter
0:40 Filtering a sawtooth wave
1:35 Subaudio [phasor~]
2:04 Randomizing cutoff frequency each ping
3:33 Commenting the code
5:12 Oops

Pure Data introductory tutorials here:


Audio Resonance (Acoustics, Synthesis, Feedback, and Sonic Aesthetics)

A quick overview of principles and aesthetics audio “resonance” in filters and beyond.

In synthesis, we often encounter resonance controls on our filters, both digital and analog, but, more broadly speaking audio resonance the property of any device, space, or system to increase the amplitude of particular frequencies.

So what? Well, that’s a good question. Here I offer some different examples of resonance, both acoustic and electroacoustic, and perhaps there are some avenues there for you to explore in your own music and sonic art.

0:00 Defining “Resonance”
0:50 I Am Sitting in a Room
1:11 Breaking a Wine Glass
1:39 “That Really Resonated with Me”
1:56 Resonant Bodies of Instruments
2:11 Feedback Loops
2:36 Resonance as Metaphor
3:09 Where’s the Art?

More fundamentals of sound synthesis:

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!

Synth Tip: Don’t Filter Sine Waves

Since sine waves are made up of only a single frequency, it’s not usually particularly effective to filter them.

Several of my students sent me Reaktor ensembles with filtered sine waves, so I wanted to quickly talk through why they’re not really the most effective thing to filter. I go through things in Native Instruments Reaktor, but the concept is applicable in whatever synthesis environment you’re working in–Pd, Max/MSP, Kyma, etc.