• intensely_human@lemm.ee
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    6 months ago

    Nyquist, thank you.

    aren’t lost they fold into lower frequencies unless filtered out

    If by “fold into” you mean they add noise to and hence distort the readings on the lower frequencies, that’s correct. But that just takes it further from a perfect reproduction.

    • Hugin@lemmy.world
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      6 months ago

      Frequency folding is the term used in DSP no need for quotes. The Nyquist frequency is commonly referred to as the folding frequency.

      And yes frequencies above the Nyquist folding frequency alias into lower frequencies. A simple low pass filter prevents this however.

      Properly filtered digital sampling produced a more accurate reproduction of the frequency range with less distortion then an analog signal.