envelope follower

[bj]

Rowena Larkins wrote:
> 
> > Unfortunately not! I had thought about this my self, but recent investigation
> > shows, that when you square a signal like a1*sin (w1*t)+ a2*sin(w2+t) you get
> > a1^2*sin^2(w1*t)+2*a1*sin(w1*t)*a2*sin(w2*t)+a2^2 sin^2(w2*t)
> > since (a+b)^2 = a^2+2ab+b^2  :-< (the old binomial pitfall)
> 
> Hang on a moment,
> you have squared the amplitude, but what about the frequency components. This
> is mathematically a 2D problem which requires complex multiplication.
> 
> There will be sum and difference components of the frequencies.
> 
> (What was the inittiators suggestion? I deleted that email)
> 
> Rowena

I have a better formula:
a1^2*sin^2(w1*t)+7ti-8pi/*7>o<-8+*5.7333. gobbel gobbel...

BJ :-)