From N. Kent Sent Fri, Jul 2nd 1999, 05:58
From N. Kent Sent Fri, Jul 2nd 1999, 05:58
> > However, in certain professional and Military applications, other kinds of > > noises are used : military noise :( > > > > -Red Noise or 1 / f squared noise > > > > -Narrow-band noises : i.e white noise processed through a highly > > selective narrow- band filter : the output is a signal of determinate > > frequency, but random amplitude... > > > > Now, there are some people who refer to " narrow-band noise" as > > blue or azure noise.... My understanding is azure is the opposite of pink noise. essentially high pass filter's effect on white noise. They wouldn't pick an obscure non primary color like azure (light blue) if it wasn't meant to be the counterpoint to pink. > > Very useful info! Does anyone know if this is what is used in the > Doepfer A118 Noise/Random module which has two knobs for Red and Blue > noise and a "colored noise" output in addition to the white noise > output? > > http://www.doepfer.com/a118.htm > > It says Red is the low frequency componet and Blue is the High frequency > component. I can check these out with my new osciloscope later tonight > :) but what should I be looking for? its got a fixed High Pass and Low pass filter. so if both the red an blue knobs are at 0 then it sounds like white noise with the high and low frequencies lopped off. (don't have time to check the steepness) I notice that at 5 on both the red and blue knobs the sound is the same as the white noise output. Then at 10 on both there is a lot of higher and lower frequency content with the middle ranges less prominent. > What you need is a spectrum analyzer. Not many of those around and they're $$$$$. Maybe there's a spectrum analyzer that works off > the audio input of your sound card. a lot of better sample editing programs throw one in, usually not with realtime respose though. but in this case it isn't required. nick