[sdiy] Harmonic content of the "sigmoid" half-sine wave

[Ingo Debus]

Am 04.06.2009 um 19:17 schrieb Jerry Gray-Eskue:

> Let me try to rephrase the question. For the sum and difference of the
> frequencies to be created we must have a Multiplication  
> ( Modulation ) of
> one frequency by the other.
>
> Will we have a Modulation of the frequency in a speaker as both  
> frequencies
> are driving a shared mechanical motion of the speaker cone?

I think this boils down to the question: are the systems involved  
linear or not? If they are, then adding two sine waves gets you just  
the sum of two sine waves. If the sum is sent through something which  
is nonlinear, then components of other frequencies emerge.
It doesn't matter if the system is mechanical or electronic. It only  
matters if it's linear or not.

Ingo