False Beats / Loose pins

[Ric Brekne]

Hi Terry

Thanks for chirping in.  Just about everything you report here 
underlines my own feelings about the loose pin / false beat connection. 
Ok... misunderstand me not.. :)  I will be the first to advise the 
application of CA glue to any pin (tight or not) displaying false 
beats... because something about that application has a positive affect 
more then a significant number of times.. just so thats out of the way.

But it strikes me that the real cause of these false beats (the ones 
that disapear when you put pressure on the bridge pin) is still 
illusive... tho it strikes me as a lot more likely that it has to do 
with impeadance / mass issues as you allude to below then loose pins.  
Frankly... I dont think loose pins really have anything to do with the 
phenomena.  Ok.. its a sexy explaination.  But its got too many holes 
... as it were.

Cheers, and thanks for the post

RicB

------------
I brought up this topic a while back and didn't get the response I was
looking for (or at least I don't think so - or maybe I just missed it - 
or I
don't remember it). My recollection of information presented by Del 
Fandrich
in one of his Small Piano Design classes (and please forgive me and correct
me if I am wrong here Del) was that some aspect of soundboard design can
affect the susceptibility of a piano to false beat production. I think it
was the fundamental frequency of the soundboard in that area of the scale -
but it could have been impedance or something else. The situation was that
if the particular characteristic (fundamental frequency?) of the soundboard
is higher of lower (or maybe just out of range) than any particular
string(s) in the same area, the piano may be inclined more or less toward
false beats.

Still, it is some defect that is the direct cause of the false beat - 
like a
loose bridge pin or a nick in the wire or whatever - or at least a
combination.

So in your case, this Bosendorfer may well have a soundboard that is
designed such that it is not prone to false beats - so much so that it can
have a loose bridge pin and still sound clean.

At the other extreme are many cheap spinet pianos that have clean wires,
tight bridge pins, etc. and still are absolutely loaded with false beats.
Presumably the designs of these soundboards are such that they are very
prone to false beats - maybe the tiny piano case is the cause! Or maybe the
horrible soundboard design can in itself cause the false beats.

Many (if not most) pianos lie somewhere in the middle. Their soundboard
design is such that they are moderately prone to false beats. If strings 
are
clean and straight and terminations are tight, you get a clean sound. 
But if
something such as bridge pins come loose, you get the false beats.

Can anyone clarify this issue? Del? Ron N.? Anyone that has attended Del's
Small Piano Design class (and understood and remembered everything - or at
least this item)? Or, of course, maybe my memory isn't all that good. I
think it's pretty good, but I really don't remember........  ;-)

Terry Farrell