New Antialiasing Technique?


#1

This looks potentially intriguing.
Anyone else pick up on it?

a|x


#2

What do you mean by anti-aliasing technique?

The plug-in you linked is not a solution to the following problems:

  • Band-limiting in analog to digital conversion.
  • Elimination of “mirror” harmonics in digital to analog conversion.
  • Synthesis of band-limited waveforms.
  • Band-limited sample playback.
  • Waveshaping/distortion.

What is it? A kind of filter that probably computes the derivative of the signal, clips the derivative, and integrates it back.


#3

The developer describes the plugin as based on an antialiasing technique he’d developed previously, for another application.

I don’t know how it actually works. I presume he’s not going to tell everyone exactly how it works.

Would it not help eliminate aliasing if placed before a DAC, in a virtual signal-chain?

a|x


#4

No, because once above-nyquist frequencies are sampled and brought in the digital domain, they move below the nyquist frequency and become indistinguishable from the actual below-nyquist frequencies.
Aliasing doesn’t happen in the DAC, it happens in the ADC.


#5

Ok, but if you were generating the waveforms internally, then passing them through this function, so there’s no ADC involved…?

a|x


#6

> Ok, but if you were generating the waveforms internally, then passing them through this function, so there’s no ADC involved…?

It wouldn’t work. The “bad” harmonics introduced by aliasing are indistinguishible from “legit” harmonics (after all they are all in the DC - nyquist band), there’s no way to tell them apart. If you can’t identify them, you can’t eliminate them, the only thing you can do is not synthesize them in the first place.