questions on clipping?

Discussion in 'Amps and Cabs [BG]' started by mastershake, Apr 10, 2012.

  1. mastershake


    May 12, 2011
    I'm not sure how correct this is, but this is my understanding thus far

    soft clipping emphasizes the lower order harmonics.

    Hard clipping has a mix slewed to the higher order harmonics.

    symmetrical clipping produces only odd order harmonics.

    asymmetrical generates both even and odd harmonics. The more asymmetrical, the more pronounced the even-order harmonics.

    I just wanted to know what you guys prefer. I think I'm looking for something that emphasizes lower even order harmonics mostly the second harmonic (octave) with the fundamental still being the dominate frequency of course.
  2. fdeck

    fdeck Supporting Member Commercial User

    Mar 20, 2004
    Madison WI
    HPF Technology LLC
    I think you've got the gist of it. For what you are looking for, you want asymmetrical soft clipping. This can be done with a number of different circuit ideas. Most simple Class-A amplifiers (JFET or triode) will do it naturally. The "quick and dirty bass preamp" circuit at my website will suffice. With op amps, a diode in series with a resistor in the feedback loop would let you add a soft clipping response that you can tailor to your tastes.
    downlowuponit likes this.
  3. Without clipping...

    A symmetrical waveform consists of only odd harmonics.

    An asymmetrical waveform consists of both even and odd harmonics.

    If take a sine wave an only clip off the top on one side then it adds even harmonics. The waveform is no longer symmetric, it is asymmetric.

    If you clip more and more off one side until it's essentially rectified - it doesn't sound so great. Adding only even harmonics doesn't mean you will get a pleasant sound.

    We also don't play sine waves.
    Basses are even and odd harmonic asymmetrical wave forms. Take a look at one in a spectrum analyzer.

    Clarinets are odd harmonics, they sound nice.

    I think the origin of "Even" Versus "Odd" is the confusion that the Odd harmonics are actually the even overtones. Even harmonics are the odd overtones. This forever confuses people when they think they got a great warm soft clipping signal that actually has a lot of strong odd harmonics that show up in the spectrum analysis.

    When people start using spectrum analyzers on "good sound" it's always both even and odd harmonics, mixed in a musical way.
    downlowuponit likes this.