M&A A

[Don]

Hi Ric, Paul and Mike,

I believe the false beat is being caused by some defect (possibly in
termination) which interferes with the ability of the strings to couple.
(As in the coupled motion of piano strings, Scientific American).
Apparently pitch lock "staples" fix the problem.

CA glue seems to work as well--perhaps because it is changing the nature of
the termination. Perhaps it makes the bridge denser or causes a change in
mass?

Changing humidity levels can affect false beats too. I've worked on a 9
foot instrument which in winter has false beats on every string from where
the agraffes stop to the top note--that in summer time has almost no false
beats. The strange part is that it is equipped with a DC system and a
bottom cover, and is kept closed up most of the time. I did not do the DC
install and I suspect the controller may be faulty in some way.

If the false beat is coming from a front duplex--then changing the mass of
the string by adding a drop of glue to the string does sometimes work.

So, how about a "bag of tricks" that work thread?

At 07:38 AM 2/18/2007 -0600, you wrote:
>Ric and Paul,
>
>I, too, was a sceptic, having done the "sideways screwdriver pressure" 
>test on the bridge pins of many false beating strings with no 
>predictable effect on the beats.  But then I had one do exactly as the 
>"myth" predicted:  The beats stopped entirely with very light sidways 
>pressure (towards the string).  A little CA at the base of the pins and 
>all the beating cleared up.   Here's what I conclude:  Loose bridge pins 
>can be the cause of SOME false beating, but is not the cause of ALL 
>false beating.  For those who have never experienced it, it will remain 
>a myth.  For me, it is now one of SEVERAL POSSIBLE CAUSES to be included 
>in the troubleshooter's bag of tricks.
>
>Mike
>
>PAULREVENKOJONES wrote:
>> Ric:
>>  
>> What has always struck me about that particular mythology is the 
>> variability of beat speeds in real (false) beating. Attributing it to 
>> loose bridge pins would lead us, no?, to believing that the loose 
>> bridge pin is moving in some way in the bridge pin hole, wandering in 
>> some oscillating manner that would create a "countable" beat, 
>> sometimes as slow as one beat per second, and certainly much faster in 
>> most instances, but still regular and countable. I share your 
>> skepticism, and return again to some length differential being created 
>> in the speaking length by way of termination deterioration, 
>> particularly the notch part of the termination creeping forward in the 
>> curve of the notch and creating a separation from the ideal 
>> simultaneous contact of the string at pin and bridge top. This is an 
>> old can of worms, I know, but maybe worth revisiting.
>>  
>> Paul 
>>  
>> *IF YOU WANT TO KNOW THE TRUTH, STOP HAVING OPINIONS!*
>>  
>>  
>> In a message dated 02/17/07 11:09:33 Central Standard Time, 
>> ricb at pianostemmer.no writes:
>>
>>     Not so strange perhaps that I have developed a healthy chunck of
>>     skeptism to this without further ado idea that loose bridge pins
>>     <<cause>> false beats.
>>
>>  
>
>
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>
Regards,
Don Rose, B.Mus., A.M.U.S., A.MUS., R.P.T.
Non calor sed umor est qui nobis incommodat

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