[ntp:questions] How bad is USB?

Unruh unruh-spam at physics.ubc.ca
Sat May 9 16:31:37 UTC 2009


"David J Taylor" <david-taylor at blueyonder.not-this-part.nor-this.co.uk.invalid> writes:

>Hal Murray wrote:
>>> I'm in a third category (probably) - as long as my PCs "sound" to
>>> have the same time, I'm happy.  Actually, I want UTC as well, but as
>>> I have a speaking clock working on two PCs it's "nice" when they
>>> both speak at the same time.  I wonder how close that needs to be -
>>> a few milliseconds, perhaps?  Here's what I actually get - all with
>>> Windows.
>>
>> The speed of sound in air is 1 ft per millisecond.  So
>> a difference of a few ms is only noticable if you are careful
>> where you put your ears relative to the speakers.

>I know it's off-topic, but how far apart in time does two singers, or 
>choir, have to be before you notice?  (No, I'm not suggesting a spoken ref 
>clock  <G>).

10-100ms
(3-30 m)
iThat is why speakers often make intelligibilty worse not better.
(the speaker sound gets to you before the direct sound.)

>David 




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