What do harmonic distortion "products" sound like in isolation?

Discussion in 'Sound Science' started by AutumnCrown, Nov 4, 2018.
  1. AutumnCrown
    I understand that second order distortion might cause a bass note to sound a bit warmer and fuller/less precise, but what does the isolated harmonic distortion product, of, say, a upright bass note sound like? Does it sound like the bass itself, without the fundamental, or just like a haze at that frequency?

    Also, how do these products behave in terms of decay and time domain compared to the fundamental note? Do they appear at the same time?
     
    Last edited: Nov 4, 2018
  2. 71 dB
    1. Yeah.
    2. Thinner version of the fundamental note. Telephones had reduced frequency bands that cut out the fundamental freuquencies of people, especially male voice, but the harmonics makes it possible for the brain to reconstruct the fundamental frequency as a "thinner" version. If the harmonics are 90 Hz apart, the fundamental must be 90 Hz etc.
    3. Like the bass itself without the fundamental.
    4. (Harmonic) Distortion products decay faster. This is pure math. When the linear term decauys to half, second harmonic decays to a fourth, third harmonic to the eigth etc.
     
  3. 71 dB
    Not very good answers maybe, but hopefully helps… …too lazy to write better stuff (nobody pays for doing this).
     
  4. bigshot
    I think if anyone has audio files of extreme examples, that would be helpful.
     
  5. AutumnCrown
    No! This is perfect... much better and muuuch more succinct an answer than I thought I would get. Thank you so much!
     
    Last edited: Nov 10, 2018
  6. Steve999
    Someone please correct me if I am wrong, but I think the distortion you get from an overdriving a guitar amp (of which I created my fair share as a teenager) is mainly harmonic distortion to the extreme. In fact as I think of it, it was a tube guitar amp. Just kind of think of Jonny Winters or Jimi Hendrix. Or you could get a super slick mellow sound out of it (Kenny Burrell or Mark Knopfler, maybe). Again if that’s not just oodles of harmonic distortion please let me know. It’s just what I always thought.
     
    Last edited: Nov 9, 2018
  7. Steve999
    Also I don’t think LPs generally got down to 40 hz, so you were left to infer the lowest bass notes based on the harmony of the music and the upper harmonics of the bass note itself. By comparison a truly well-produced 40 hz tone is rock solid sound.
     
  8. VNandor
    If I understand it correctly, any kind of distortion that adds harmonics which have a multiple of the frequency of the fundamental harmonic counts as harmonic distortion. So if the original tone is a 50Hz sine wave and that gets distorted, additional frequencies will show up on the spectrum at 100Hz, 150Hz 200Hz etc. If other frequencies show up (that aren't multiplies of the fundamental) as the result of the distortion, it isn't purely harmonic distortion. Harmonic distortion can sound good depending on the context, as far as I know (but I might be wrong) certain types are being used in genres like rock or pop for mixing. It's definitely being used in electronic music. Tube amps are also being liked by some due to the distortion it causes when it's a little overdriven.

    I think both digitally applied hard-clipping and soft-clipping count as harmonic distortion as well as analogue distortions like tape or valve saturations. These are typically symmetric distortions, which means both the positive (top) and the negative (bottom) side of the waveform is being distorted in the same way. Symmetric distortions can't add even number harmonics if you count the fundamental as the first harmonic. So if a 50Hz sine wave gets symmetrically distorted the harmonics will be at 150Hz, 250Hz, 350Hz etc.
    Asymmetrical distortion can add even number harmonics as well and probably also counts as harmonic distortion.

    Anyways here are a couple examples of harmonic distortions if I got the definition right at the beginning:
    https://drive.google.com/open?id=1NPct0vYjl3pqAp_7D3hNQIVCEwScoZir
    The first is hard clipping, then soft clipping, saturation, and asymmetrical distortion. They are also being played with and without the fundamental.
     

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