[sdiy] Truly red noise

[Theo]

Did you notice in the article all the way down Brown noise?
Spectrum given is 1/(f^2) and the color Red is suggested as in this case
Brown is not a color.

A Pink noise filter is basically a LP filter with -3 dB slope.
This is often build as a single RC LP were the R is one resistor and the C
made of multiple cap+resistor combinations.
Swapping the resistor and caps+resistors so that the resistor goes to ground
and the caps+resistors become the input should change it into a HP version
for Brownian noise.

Cheers,
Theo



----- Original Message -----
From: <allenre at umich.edu>
To: <synth-diy at dropmix.xs4all.nl>
Sent: Friday, June 25, 2004 7:05 AM
Subject: [sdiy] Truly red noise


> A tangent to the white noise thread--
>
> I was reading a book on electronic music awhile back and I remember coming
> across some definitions for audio noise (these are off the top of my
head):
>
> white/gaussian noise - power of 1 (unity) over the spectrum
> pink noise - power of 1/f over the spectrum
> red noise (this is a little foggy) - power of 1/(f^2) over the spectrum
>
> If this is correct, I should be able to get red noise by taking the
negative of
> the derivative of the pink noise, right?  How would this be done
> electronically?
>
> Now I've seen the "colors of noise" article here:
> http://www.hoohahrecords.com/resfreq/articles/noise.html
>
> But there is no math given for the red noise.
>
> Ryan Allen
>