Please Demystify the Chladni Sequencer

[futureaztec]

I looked in the documentation but did not find too much. I looked for some kind of Eurorack module that may have inspired it, but didn’t find anything. Then I checked on the old forum but this didn’t bring my head around it fully. Maybe because we can’t download the patches straight off the old forum. So I thought there might be something helpful in the zip file of old forum patches but nothing seemed to fit the bill.

Maybe this could get a standardized module post with ins and outs etc. What does that unlabeled knob do beside the x and y knobs?

[robertsyrett]

Chladni Plates

I believe the Chladni sequencer is a take on a cartesian sequencer, but a very eccentric one. This is my guess, but I think the LED display is supposed to evoke those symmetrical resonant node shapes seen in Chladni plates. Usually one input is the x axis and the other is y axis (think make noise rene sequencer), but on this one the two modulation inputs map the whole 64-step sequence to the modulation range (0 to 1) and scan the rows (x) top to bottom and scan columns (y) left to right. Each of those have an output with a gate output which is tied to a change detector rather than a clock. Finally there is a combined output, which I think might be bugged, because it is supposed to be a combination of the two but actually doesn’t output much of anything.

Because everything is unlabeled you have to put labels on them to discover what is happening, despite there being a little description of what is going on. Also, unraveling the Chladni mystery is a good example of why cable highlighting is important, as this 8x8 grid of knobs produces some magnificent spaghetti.

I mean there are so many cables it visually aliases.

I think this probably an older @biminiroad module and so the emphasis is on exploration and visual appeal, but I think it also could be better. For example, the combination of the two outputs is better left out. People can combine two signals on their own. Also the values of 64 knobs is dubious. In addition to being a patching nightmare you usually end up just turning knobs at random. I think a alternative interface would be to have 4 knobs that affect a 64 step sequence in a symmetrical way.

Here is a sketch of what I’m talking about: Chladni Kaleidoscopic Matrix.audulus (97.0 KB)

[futureaztec]

Kind of Interesting for some FM crossover blends.

Plate Seq Experiment.audulus (1.7 MB)

[futureaztec]

Awesome. Very appreciated. Feels like a good way to explore logical patterning with all of the small overlooked modules that are bundled in the menu.

[futureaztec]

To be fair, I found some good notes on the original sequencer. It helps to watch this video and see the lights cascading from the centre out and back in:

Here are some details I found helpful. According to @biminiroad:

This sequencer uses 0-1 LFOs instead of clocks to drive the sequence step selection. If you use a saw wave input for both sequences, the X sequence is read left to right, top to bottom, and the Y sequence is read top to bottom, left to right. To reverse direction, simply use a reverse saw wave, or even a triangle or sine - or rectified audio! Anything really.

A third sequence is created when X and Y intersect - this is the = output.

The field of values are all scaled 0-1. Best results are obtained when you feed back sequences to the steps themselves.

The two controls next to the visualizer are max step controls. The one next to these towards the middle turns the sequences on an off in various combinations.

The difference between a clock-driven sequencer and an LFO-driven one is that a clock-driven sequencer needs all sorts of special count up/down apparatus to move through each steps, especially if you want to do different movements like backwards, ping-pong, pendulum, etc. In this module, you can just send it any kind of modulation signal, like a frequency modulated LFO, that would just be impossible to recreate with a traditional clocked sequencer.

The LFO does not have a negative cycle, since all of the LFOs in the new library are offset to a 0-1 range. Slow the LFO down and attach different shapes and you’ll be able to observe what’s going on.

Every time the sequencer moves to a new step, it generates a gate signal. Each step is ranged between 0 and 1. The modules at the m outputs are translating that 0-1 m signal in to an -4 to 4 octave signal, which drives pitch selection.

Also, the sequencer has two outputs - a number that ranges from 0 to 1, and a gate that is either on or off. You have to translate that 0-1 signal into a Hz value and feed it to an oscillator, which the other modules automatically do - you can’t just attach the outputs to a speaker node. In case you don’t want to use the other patches that are there, here is a translator that will take the o signal and turn it into a Hz signal.

So I am curious about a patch the would cause the lights to behave like a Chladni plate. But also curious if this is possible with @robertsyrett’s take on this design. I guess I would have to try patching the knobs.

[robertsyrett]

I recommend the quadrature sine LFO

[futureaztec]

I thought I might try to modulate with envelopes – make a keyboard synth out of it.

Chladni Synth v0.1.audulus (502.2 KB)

Then you sit around for hours tuning it.

[biminiroad]

@robertsyrett

Finally there is a combined output, which I think might be bugged, because it is supposed to be a combination of the two but actually doesn’t output much of anything.

Robert you got the rundown of the sequencer right except for this part - it’s not bugged. That extra output is only resampled whenever the X and Y sequence arrive on the same step at the same time. Depending on your knob settings and LFO input settings, it might not change much.

I love your mini version of it - certainly much more workable and approachable.

And yeah the quadrature LFO is the bomb - I need to make an octature version too.

@futureaztec - yes, all of the modules are documented both inside the module themselves and on the modules reference. Until I finish the hyperlinking, using cmd+f to find things is the easiest way to navigate it.

[biminiroad]

This plate patch is really great, especially when you mess with the balance of the VCOs!

[futureaztec]

When we think of sequencing, there are tendencies to treat it as a stepped, generally left to right, top to bottom process. While there are exceptions, these are treated as such because of this initial standard.

What about Logograms? One of the finest films I have seen in recent, was Arrival. Although a few people I talked to say the didn’t “get it,” I sat mesmerized in the theatre as concrete linguistic ideas dovetailed with surreal, grey-space (nearly psychedelic) possibilities about time, linearity, and the possibility for our lives as compete objects to be formed in total based on the immediate present perceptual stance we take.

But, what about Logograms? When I looked into Chladni plates it was clear that the geometric possibilities in sound had to do with non-linear or parallel interactions of patterns. So I adapted @robertsyrett’s “sequencer” as an envelope control so that I could better capture the blooming notion that appears in the plates. Looking back at the film Arrival, there is something remarkable about those logograms that are presented before the backdrop of tense military negotiations and a simplified farmed landscape. It has to do with how analogies like “games” inform the way that we interpret ideas. In a total idea, in an idea that exists as a completed form, when you alter one aspect, the ‘shape’ of that form changes, relatively.

Bertrand Russell

[futureaztec]

I should clarify something that I left foggy above. I kind of tacked on a picuture of Bertrand Russell at the end here without explanation for a couple of reasons.

Sometimes I like to post some ideas because it helps me think and it helps me get beyond the bad ones. Russell is important, in the very least for the correction he made to Gottlob Frege’s logic. While I appreciate Frege in the hands of people like Robert Brandom, there is a Frege that rubs me the wrong way. In any case, one thing some people don’t realize is just how much philosophy has done for computer science, computational research, mathematical modelling, etc. So Russell discovered a paradox that was damning to Frege’s work. John von Neumann had a way of distinguishing between sets and classes, which addressed this paradox. And, as we race along here, incidentally it was von Neumann who provided the problem subject for John Conway to later run his research for the Game of Life. Full circle. Logogram?

Russell believed Chinese symbols represented complete ideas or ideograms, which they are not. It seems likely that this inspired the logograms. It is funny in a way though that people tend to get behind Frege and label Edmund Husserl as having a shaky psychologistic logic (the idea that judgements cannot be understood by appealing to mental phenomena). I agree with Frege here – or, having looked at the subtle genius in some of his surprisingly easy to read works like Foundations of Arithmetic, his ideas are indispensable. But there is something non-sequential about intuition, something immediate, maybe even logographic. Perhaps, then we need to get back to Husserl to think about Conway.

[robertsyrett]

@futureaztec I don’t always know how to respond to your posts as they seem to expand beyond the realm of audio design, but I always enjoy reading them. Sometimes even revisiting them and exploring the links.

[26PM]

NICE. My mind just widened in its views concerning sound and shape.