[sdiy] jitter analysis

[Czech Martin]

>  It is
> not possible to measure the jitter with any precision after 
> sampling it at
> 44100Hz. 

why?

We're after some effect, the measurment data is only helping
us to understand. But it is not the real target.
The target is to understand.

Perhaps I'm completely wrong, but the ear is somehow a bandpass
system (fromm my hearing experiments 30 -17000 Hz).
Above or below I can not tell if a full level tone is on or off
(headphones).

If you say that the Nyquist lowpass filtering will allready destroy
the effect, I suspect that it will also not reach the ear-drum
or cochlea, since this is allready bandpass filtering, not to speak of
the nervers and brain.

So , as long as no profound error in my reasoning can be found,
it is not clear to me why such obvious effects like livelyhood
of a wave should not appear in the usual 22050 Hz sampling
bandwidth.

Perhaps the figures you get during measurement must be intepreted
with keeping in mind that it is bandlimited. Of course.
But the effect must be somewhere in the samples, otherwise
it is getting esoteric.

Hah, this is also the argument that I should have used when Magnus
told me that 44100 Hz sampling will not allow for precise measurement.
I mean, he was absolutetly correct!
But my question was wrong! It was: How to measure the jitter?
But it should have been: how to measure the jitter which remains
after bandpass sampling / lowpass sampling?


m.c.