Patch 14: Modular is a Machine that Goes PING!

With the start of April I am officially in preproduction for my next album, which means we’re gonna have some sound designy patches for a while! One of the goals of this preproduction phase is to make a bunch of new sounds to use when I start writing and producing in a few weeks, so it’s a good time to go over some fundamental sound design techniques, and I thought I’d start with one of my favorites: pinging.

It works like this: take a filter and set the cutoff kind of low and the resonance really high — but not quite high enough to self oscillate — usually just right before that (What’s that? You didn’t know filters could self oscillate? Yeah, they can –most of them– and it makes a lovely sine wave; it’s actually one of the easiest ways to get a pure sine wave!). Then you hit it with a tiny little signal — the titular “ping” — and the filter will ring out and give you a tone that delays relatively quickly (maybe, depending on the filter, the resonance setting, and the ping you use). It makes great percussive and drum sounds, and with some tweaking can be used to generate a bunch of other cool sounds as well.

So that’s the theory, at a high level; let’s look at the practice. I spent most of the week building ping patches and recording sounds with them, some of them quite elaborate (I actually got a decent acid thing going at one point, but that went well beyond basic practices). After half a dozen or ten potential patches, I settled on what’s almost the simplest possible version of this.

The filter we’re pinging is QPAS, because it’s an incredible filter in general and in particular it begs to be pinged. I tried all the outputs and for this exercise I landed on the bandpass output, using just the left side (notably, on this filter you get a different result if you use it in mono vs stereo, so I wanted to specify it here). For the ping, I settled on the Dynamic Envelope output of the 0-CTRL (that’s right, you don’t even have to ping with audio signals — a gate or trigger is often plenty) after trying lots of different stuff. You do get subtly different results with your choice of ping, so do experiment here! Just keep them short, or you’re moving beyond pinging into something else.

As you can see from the photo at the top of this post, I tuned the cutoff and resonance pretty low here — generally you’ll run your resonance MUCH higher, but a) the QPAS has A LOT of resonance, so it gets tuned a little lower, percentage wise, than most filters, and b) I’m modulating the resonance with the Strength output of the 0-Ctrl, which essentially means the harder the “hit” the longer the sound rings out, which is very natural/realistic! That’s actually a new trick that I just kind of stumbled on while experimenting with variations for this post. (Remember kids, this is gardening, not architecture.)

The pitch control of the 0-CTRL is going to the QPAS FREQ2 input (unattenuated control of filter frequency, not sure it tracks v/oct but I don’t care and it doesn’t matter for this operation). And because we have one more channel of control (Time, which I attenuated out of use in the 0-CTRL, freeing it up to solely be a source of modulation), I sent that to the left radiate control, which moves the various filter cores around, giving different results. For a final occasional touch of hands-on control, I used the Touch output CV of the 0-CTRL to control the right side Radiate control.

And that’s the whole setup! In usage, what I do is set the sequencer running and record its output (into the computer, the MPC, or a portable recorder, depending on what my plans for it are/what else I have set up). As the recording goes, I tweak settings on the filter, the sequencer and any other modules I might have hooked up. Again, none here, but often I’d have a distortion for other effects in the audio chain, and possibly more sources of modulation, depending on the filter and what I am trying to accomplish.

And what can you expect to get from these pings? Well, mostly drums and percussive noises. Some really nice bell tones in the higher registers. Glass and wood sounds. Toms, congas and tablas if you add a pitch envelope of some kind, or the filter is wobbly on its own. Thunks, klacks and bumps. At higher resonance levels and noisier inputs, you can get some interesting synth tones. And of course, processing these sounds offers its own wealth of possibilities.

It’s worth noting the QPAS has a bunch more inputs that I could be modulating, and often would, to get more variety in the results. The results then get cut up, run through effects, etc, and made into drum kits, synth sounds, etc. In the past two weeks I’ve made three kits worth (~ 50 sounds) of samples using variations of this technique.

Here’s a little loop based on this exact patch. My intention in making this was simply to generate a bunch of one-hit samples I could cut up, but the 0-CTRL is so inherently musical I found myself straying into actual performance and ended up with some potentially usable loops! Again, it’s gardening.

This is a core synthesis technique but doesn’t get talked about enough. You don’t have to have a modular synth to do it! You don’t even need an analog/hardware synth. Any synth with self resonating filters should allow it. On a traditional synth you probably won’t be able to send a trigger directly to the filter input, so there you’d use noise or a very harmonically rich sample/waveform with the shortest possible attack and decay envelope, so it’s just a blip — just enough to excite the filter into resonating for a second before it decays away. I will admit, the results aren’t usually quite as interesting with digital synths and/or some analog synths with “tame” architecture, but it can still be worthwhile, and fun, to experiment.

Not sure what I’ll get up to next week, but it will probably be more sound design. See you then!

Here’s a video version with a bit more audio in the intro/outro.