M&A A

[RicB]

Hi Paul.

The variability of beat speeds you mention bothered me as well for a 
long time.  But lots of reading on the subject removed my objection per 
se.  What finally made the light go on there was Jim Ellis's article 
from way back.  He used a pendulum analogy to show that the degree of 
springyness a support (i.e. termination) has can essentially lengthen 
the effective arm of the pendulum and slowing the period. It does this 
by moving in phase with the oscillation of the pendulum. The more 
springyness, the greater the complimentary oscillation and the faster 
the beat rate.  That in itself tho leaves one with a single slower 
frequency... not two frequencies needed to create a beat rate.  Ok... so 
a string vibrates at many frequencies... but it still would need to have 
to simultaneous nearly identical lengths for a beat rate to happen... 
and this needs to happen at the termination..... Ok again... the string 
can vibrate at same frequencies in several different planes at the same 
time... and then this becomes possible... at least as far as springyness 
of the termination in general is concerned.

The problem with fitting a loose pin into this as something that 
<<directly causes>> false beats is that one attempts to go back to Jim's 
article... define the pin as the pendulums <<support>> and as such must 
claim horizontal movement of the pin as being the culprit. This gets 
problematic immediately. Jim himself denies that (stricktly) horizontal 
movement of the pin.. or that any in phase movement by the termination 
in any /particular/ direction at all is at root. In phase movement at 
the termination occurs in all directional planes of string vibration.  
He cites general springyness of the termination as a whole, tho is the 
first to go along with the idea that bridge pins can be a contributing 
factor in the general condition. I also wonder about the sidebearing of 
the string in this picture... it would seem to me that even if a loose 
pin was involved.... the least likely direction for in phase springyness 
would be the horizontal exactly because of the side bearing the string has.

Then there are some empirical facts that simply cant be ignored.  Purely 
from a statistical standpoint there is really no identifiable 
correlation between the occurance  of false beats and loose bridge pins. 
Way to many cases where the opposite happens... way to many cases where 
the same false beat occurs when pins are actually tight. Then there is 
also this famous <<test>> with the screwdriver.  Why does  pressure with 
the screwdriver actually cause the false beat to start up again and 
speed up with more pressure when you've first put enough pressure on the 
pin to quite a false beat ? Why does the application of mass to 
neighboring bridge pins or back side pins also (sometimes) affect the 
presence of a false beat ?

Strikes me that the whole presently and popularly accepted idea that  
bridge pin is /thee/ support for the string and that it /causes/ false 
beats is a pretty large oversimplification of the whole thing.... likely 
based on an equally over simplifed interpretation of articles like 
Jims.  And as is very common in our trade the collective we jumps on the 
wagon declaring a new (and just as magical as any previous) Truth .  Viola !

For my part.... I'll keep adding CA in appropriate circumstances... 
because it does help... (another discussion entirely :) )... but I'll 
also keep wondering about what the heck is really causing false beats.  
Clearly the loose pin thing is to thin.  Actually... when it comes down 
to it... the recessed notch bit seems much more likely as it allows the 
string itself to have a partial vibrating in several planes at the same 
time at different lengths... the bridge pin doesnt need to even get 
involved here. For that matter... string imperfections at or very close 
to the termination can cause a string internal springyness that could be 
at root.   The whole thing needs IMHO a lot more looking into before any 
definitive explanation is available.

Cheers
RicB


    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!