[pianotech] Additional Information Regarding False Beats

[Richard Brekne]

    I am a frequent reader of this list and it has been a great source 
of information in my studies.  Thank you all for generously sharing your 
knowledge.

    -Zane Omohundro
 
Hi
Reading the many opinions on this as so many other piano subject matter 
is sometimes almost as entertaining as observing the various opinions 
there are relating to Cosmology.  You will find the greatest part of the 
"information" available is really opinion and conjecture and there is 
some smaller amount of bold faced pure facta.

A recent article in the Journal by Jim Ellis with contributions from Del 
Fandrich and a couple others takes the string isolated from the effects 
of the soundboard and bridge assembly and shows some interesting 
results. John Delecour posted a link to a paper done on the subject 
matter some time back. The Five Lectures, tho not directly relevant are 
worth looking through as they get into some of the possible ways the 
soundboard and bridge assembly can get into the false beat picture. 
http://www.speech.kth.se/music/5_lectures/contents.html

I have done quite a bit of informal experimenting myself on the matter, 
tho have not published a formal study (yet) and found that the 
observable relationship between loose pins and occurrent classic false 
beats is from a statistical point of view is actually quite random. At 
the same time the addition of substances such as cellulose lacquer, CA 
glue, epoxy and some others to the bridge pin holes has a statistically 
significant impact on the reduction of these false beats. Drawing 
conclusions as to why this happens is another matter and I maintain 
there is no hard evidence to support any of the conclusions usually made 
and voiced.

Interestingly, relating to the loose pin argument frequently floating.  
You can take 10 very clean sounding strings, replace the bridge pin with 
an undersized pin creating a very loose pin situation and find that none 
of these same develop false beats.  You can also simulate the stated 
condition that supposedly causes the false beat (flag poling pins) by 
inserting a 2 mm brass bushing under the string at the center of the 
bridge extending back to the distal bridge pin and find no development 
of false beats. You can also experience that a false beat IS evident and 
either of the alterations above actually eliminate it.... tho this 
doesn't seem to happen more then a small percentage of the time.

I don't pretend to have the answers as to why things behave the way they 
do.... but my approach to this kind of thing is to directly observe 
various isolated conditions to see if the observable results match up 
with what those who rely on some understanding of theory claim should 
happen. 

Cheers
RicB