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From: alex@bilver.uucp (Alex Matulich)
Newsgroups: rec.music.synth,comp.music,rec.music.makers
Subject: Re: White Noise???????
Message-ID: <1990Dec17.224535.23225@bilver.uucp>
Date: 17 Dec 90 22:45:35 GMT
References: <12263@bsu-cs.bsu.edu> <71303@unix.cis.pitt.edu>
Organization: W. J. Vermillion - Winter Park, FL
Lines: 36

In article <71303@unix.cis.pitt.edu> mpmst1@unix.cis.pitt.edu (metlay) writes:
>In article <12263@bsu-cs.bsu.edu> travis@bsu-cs.bsu.edu (Travis Michael Banks) writes:
>>
>>Can someone please tell me what WHITE NOISE is?
>>I've seen it referred to on several occasions and have no idea what it is???
>
>White noise is a kind of audio signal where each frequency is represented
>with an equal amount of power.... it's "white" in the same way that light
>[...]
>Alternatives are types of noise where power output is weighted with respect
>to frequency: the best known example in our field, used for testing rooms
>for mic placement as well as on the better analog synths, is pink noise,
>which follows a frequency dependence considered more interesting to the
>human ear. Its dependence is a very simple math formula involving one over
>the frequency, but I don't dare try to quote it from memory or the zillions

Actually, the simplest definition of pink noise is a signal composed of
all frequencies, weighted in such a way that there is equal energy
in every octave, rather than equal energy at every frequency in the
case of white noise.

Pink noise is generally used for testing audio equipment because it
won't blow your tweeters at high volume levels like white noise can.
For example, say you have two speakers, one designed to respond between
500-1000 Hz, and another designed to respond between 10,000-20,000 Hz.
Each speaker has a response range of one octave.  But look how many
more "Hertzes" there are in the higher octave!  Sending white noise
to the higher-range speaker will result in 20 times more power being
sent to it than the lower-range speaker!  Using pink noise would cause
equal power to be transmitted by each speaker in this example.

-- 
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