4 Oct
2010
4 Oct
'10
12:28 a.m.
On Fri, Oct 01, 2010 at 09:36:53AM +0200, Jens M Andreasen wrote:
Another example: Play two sinewaves, 1 Hz apart. Every
second they will
cancel out each other completely - even if they undeniably are both
present.
Yes, but this is nothing special. The two cancel at exactly one point
in each one second period, and that point need not even correspond to
a sample. The 'impulse' example is different: *all* samples are zero
except one per period.
But OTOH, if you would upsample the impulse signal (or turn it into
its analog form), it would not be zero most of the time, and the zero
points would be the exception like they are in your example - they
just happen to coincide with the samples at the original rate. So
in fact that is not really different.
Which again illustrates that 'the samples are not the signal', and
that any simplistic way to interpret them easily leads to the wrong
conclusions.
Ciao,
--
FA
There are three of them, and Alleline.