IF YOU WANT TO KNOW THE TRUTH, STOP HAVING OPINIONS! In a message dated 02/18/07 05:44:48 Central Standard Time, ricb at pianostemmer.no writes: 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. I love watching how your mind works this through, Ric. It's as if your mirroring my mental snail trails through the high grass! 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. Ever since Jim's observations on the "springiness" of the termination which I have wholeheartedly endorsed without drawing deeper conclusions yet from them, the notion of the primary oscillating phases of string vibration (horizontal and vertical and the effects on sustain and decay) have made me want to find someone with lots of money and the time to do this research. Does any of the "wapin" research bear on this at all, that is the angle of the pin and "lock position" of the pin and impedance results at the bridge? 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 ? Beats me :-) 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 ! Or, there's always room for cello, too. But I agree with you that because there is not enough real research being done, that we as technicians (not engineers) tend to, as you say, jump on the current bandwagon instead of allowing the wagon to continue to move and collect data and observable phenomena. 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. I couldn't agree more. Warm regards, Paul -------------- next part -------------- An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/20070218/5d56bb0c/attachment.html
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