false beats from ?? -...

Ric Brekne ricbrek@broadpark.no
Mon, 19 Dec 2005 00:32:25 +0100


Robert Scott writes:

When a bridge pin is loose, it does not resist right-and-left motion as 
well as the bridge cap resists up-and-down motion.  Therefore the 
right-and-left vibration effective speaking length is slightly longer 
than the up-and-down effective speaking length.  This is consistent with 
the  observations of performing the screwdriver test for loose pins.

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Except for the fact that you can insert a loose pin into a false beating 
strings pin hole and the false beating can dissapear.  Or except for the 
fact that you can tighten the same false beating strings pin and not get 
an improvement.  Then too is the fact that if  sideways pin motion was 
the case one would not notice the false beat until after that intial 
phase of string vibration. But that is not the case.  Further... given 
the amount of side bearing on the pin, and given that the pulse that 
hits the bridge will always put more pressure on that pin, I have to 
wonder about the speaking length being changed idea.  Further... one can 
observe when the bridge pin is not in the same place as the notch that 
the string also has a thusly undefined termination without any 
consistent occurance of falsness.

There are other problems with this concept as well.  If there was a 
conextion between pin loosness / sideways motion / and false beats then 
one would expect there to be a correlation between the speed of the 
false beat and the degree of looseness. Clearly there is none.

I dunno... just doesnt add up to me really this loose pin thingy.  I 
think there must be another mechanism at work here.  JMHO

Cheers
RicB



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