[email protected] wrote:
On 28 Jan 2013 17:56:10 GMT, Rob <[email protected]> wrote:
In my opinion, when you think a crystal is not accurate enough, relying
on single-shot time measurements via radio internet connection will
*certainly* not be accurate enough. The protocols used on radio
channels are not symmetric, because the topology is not symmetric.
(there is a single base station communicating with a number of clients)
Typical crystal accuracy is in the same ballpark as what you require.
When you see significant differences, it is more likely that the actually
used crystal frequency is different from what you are reading from
some system information call.
Yes, that may be true. Smartphone manufactures, for whatever reason,
sometimes design a sound system that delivers 22,150 samples per
second when my app requests that more standard 22,050. By the way,
this has not been a problem with Apple devices (iPhone/iPad), which
all seem to be close enough to nominal without custom calibration.
But Android devices and Windows laptops are a different story.
Can you modify your software to be rate agnostic/flexible?
the samling rate error you show is 4000ppm while crystal deviation
should not go beyond 50 .. 100 ppm ( 1 "cent" should be ~416ppm !?)
uwe
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