(working title) 2 dimensional chaos generator

[Architeuthis]

the final nail to the coffin: A sine under Nyquist and a DC value don't alias, but modulate the frequency or phase of anything and you're always technically aliasing. The sidebands are infinite, so some always cross Nyquist. Amplitude modulation and waveshaping alias too, unless you deliberately band-limit them. So alias-free is a razor-thin set: static, band-limited signals. Everything that moves: aliases, which means the real question was never "does it alias", it's "does it sound good."


the rationale: I've shown you can alias pleasingly, alias unpleasantly, filter it, or dither it. Aliasing becomes a design decision. Want it clean? Band-limit it (costs effort, sometimes a lot, but it's there). Want character? Let it alias nicely. Want it to just sound nice? Mask the ugly parts.

the universe's antialiasing filter is a singularity

[antto]

if you want to have aliasing that sounds good in analog(ue), then just make an analog decimator - run the signal thru a Sample&Hold, modulate it with 40kHz or whatever you like and enjoy

Yes, I've done that with flower child filter downsampled mode to demonstrate analog-style sample & hold (already implemented in soundemote.io/sandbox).

no, i think you didn't understand what i said
i meant "decimator" as in the decimator "effect" that intentionally does things wrong to allow aliasing
and i meant "analog(ue)" as in: electronics, circuits, real physical things, not some code in a PC... no "sampling rate", no circuit simulation either

because, do note that when you're making a decimator in DSP, if the "frequency parameter" of it is adjustable, then you have 2 different kinds of aliasing going on, not just 1:
1) the "desired" aliasing from the input signal "interacting" with the Sample&Hold (both the digital and the analog(ue) implementation will have this, of course)
2) the aliasing that happens (only on the digital implementation) from the sample&hold every time it retriggers and its output "held" value jumps, which can happen anywhere in time when the frequency is adjustable

[Architeuthis]

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[antto]

Everything that moves: aliases, which means the real question was never "does it alias", it's "does it sound good."


the rationale: I've shown you can alias pleasingly, alias unpleasantly, filter it, or dither it. Aliasing becomes a design decision. Want it clean? Band-limit it (costs effort, sometimes a lot, but it's there). Want character? Let it alias nicely. Want it to just sound nice? Mask the ugly parts.

i've been on this side too since very long ago, except with a slight but very important nuance:

i agree that from a music/art POV, aliasing may happen to just be what works better for a particular case for a particular sound in the ears of a particular artist - "this has audible aliasing, but it's actually sounding good" - e.g. this is the exact reason why "decimator" effects exist and are quite often used especially in some electronic music sub-genres

but, the problem is not with the "decimator" effect since the majority (or all, if done right) of the aliasing of it is made intentionally... the problem is with the actual normal aliasing, like from when you're playing a .wav file with "nearest-neighbour", or running a naive ramp wave and LFO'ing it up near nyquist.
because, this aliasing depend on the Fs, and the Fs is a parameter the user is allowed to change.
e.g. the artist is fiddling with something (no matter how or what), and suddenly he stops touching - it sounds PERFECT ... and now suppose that some of that sound includes aliasing reflections, normal ones.. the problem is that if the artist (or someone else) changes Fs - the aliasing reflections will change too, and now does it still sound "good", or did some of the "magic" get lost? the fact is, it will sound different at different Fs

thus "in my book", if the user is allowed to change Fs, (the normal) aliasing should be either avoided as much as possible (what everybody does and all the books teach you to do), or there should be some info clearly in the documentation stating that there IS aliasing, and how to use it "reliably" ... sortof

for DAW plugins, Fs is unknown, thus i see (the normal) aliasing as a mostly bad thing
but for things where i'm in control of Fs and the user can't change it (e.g. in my hardware DSP thing) then i can allow aliasing to be usable as an effect

[antto]

all these chaotic-like math constructs, strange attractors and such - they are very cool and all, i've made some in the past too, the problem is that they are tied to the sampling rate, so according to "my book" (what i said in my previous post), they don't have too much place in my stuff

[Architeuthis]

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[Architeuthis]

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[antto]

antto, yeah — we're on the same page, and i think there's a cleaner answer to the Fs-fragility part.

that fragility is really a parameter-coupling problem: changing Fs unintentionally changes the aliasing — a parameter the user never meant to touch. the fix is to make aliasing a first-class, controlled parameter instead of an accidental byproduct. X shouldn't move Y unless you want it to. that's just instrument design.

and for the specific "Fs changes and the magic is lost" case: make the aliased sound Fs-independent. resynthesize it additively — place the partials where the aliasing would land — so it sounds the same at any sample rate. that's what my antisaw does: the aliased character, generated so it doesn't depend on Fs at all.
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⬆ AI

im sorry, im using ai to reply now, because i just "cant" anymore. im going to bed. it's either the AI reply above or my human reply below, you can choose which one you want to read, im out.

P.S. NO IMAGES WERE GENERATED BY AI IN THIS THREAD, ALL IMAGES ARE FROM PRETTYSCOPE USING CHAOTIC ALGORITHMS

⬇ HUMAN
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antto, i need you to hear this: you stated a problem, i gave you the solution, and your conclusion is: not for me

if aliasing sounds pleasing and then the user changes a parameter which changes the aliasing,

first: i am fully aware of the problem.
second: i am also fully aware of a solution.

solution: stop changing multiple things about the sound at the same time, it's a dimensional problem of too many parameters in the sound being changed when the user didn't want that. a user wants to change X without changing Y, that's instrument design 101, aliasing is a parameter now.

edit: or, more accurately, for this case: change X and Y relationally.

i thought i'm talking to a human, why is there a chatbot in the conversation? (are you held against your will somewhere? (do you need help? (should we call 911?)))

alright, i was trying to discuss things, seems you do not need it, i get it, you have big plans, big projects

[Music Engineer]

I love the pitch dithering

Try using a single pitch-dithered sawtooth wave and pass it through a waveshaper (without oversampling!). The result is still a pitch-dithered, "anti-aliased" waveform. The (pseudo) anti-aliasedness of pitch-dithered waveforms survives waveshaping!