Re: BBC Radio 4 'Feedback' (13:30 Friday) - Discussion about move to

In message <h5bhk3$sn7$1@xxxxxxxx>, boltar2003@xxxxxxxxxxx writes
On Tue, 4 Aug 2009 23:04:06 +0100
"Brian Gregory [UK]" <ng@xxxxxxxxxxx> wrote:
In the context of audio would it matter if a 21kHz signal became a square or
sawtooth?
The harmonics start at 42kHz -- well out of the audible range.

I wish people would stop talking about harmonics like this. A pure square does
not have any harmonics in the real world - only inside the mathematical
intepretation of a fourier transform. In the real world it is not an infinite
number of sine waves increasing in frequency and decreasing in amplitude.

Uh? Have you ever looked at a squarewave on a spectrum analyser, wave analyser or other device which 'looks at' the components of a signal in the frequency domain? You might be surprised!
--
Ian
.

Relevant Pages

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