Harmonics: a "why is the sky blue?" question

[xtian]

Imagine feeding a sine wave into your preamp, and pushing it so it starts to clip. When you look at this wave on a scope, you can't "see" the added harmonics…it just looks like a sine wave with the tops and bottoms clipped off. The added even-order harmonics don't actually come into existence until you push this waveform through a speaker, and that speaker cone, because of mass and inertia, creates the harmonics because it can't conform to the clipped portion of the wave. That is, while the waveform is in clip, the speaker is still vibrating, until it returns to meet the un-clipped sine wave, and this is where the harmonics are created.

Am I wrong?

[Reeltarded]

They are masked. Try feeding it a square. The harmonics will appear as sine waves following each order up to and beyond dog whistles.

I can't remember exactly the science, but it has to do with sine being fundamental in all other sounds.

When you push the full wave through something else it is affected by those processess. That is why you see it after treatment.. btw.

[martin manning]

The clipped wave is what it is because it contains the higher harmonics. In other words, the fundamental (your input sine wave) plus a number of harmonics results in the clipped waveform. The speaker's inability to reproduce that waveform as sound pressure will actually remove some of them from the audible sound.

[rsi]

If you take that squared off wave and do a fourier transform on it, i believe you will see the harmonics separately from the sine wave.

[xtian]

Woah! Just, woah. *processor busy icon*

[LeftyStrat]

It's fun to take a sine wave and add the additional harmonics one at a time and look at the resulting waveform. Add only the odd harmonics and you will gradually approach a square wave.

http://www.slack.net/~ant/bl-synth/4.harmonics.html

Add only the evens and you end up with a half rectified sine.

[xtian]

Many thanks for the illustration, Lefty. Perfect.

[LeeMo]

When I sold stereo equiptment in the mid seventies, I remember reading somewhere that a square wave was a fundimental wave with an infinite number of harmonics. Therefore, as a clipped wave approaches a square wave , the harmonics are passed through the crossover to the tweeter and the smoke escapes ... never to be re-captured.

LeeMo