noise

[Don Price]

I work on a small Kimball grand (La Petite) which my customer purchased new
5 or 6 years ago.  The customer has always complained of a rattle or buzz
with the two or three notes aroung G5, which I have not been able to
correct  (In fact, I have never been sure that I could detect what she was
hearing.  And I am sure she was not just hearing things in her head.)  I
have tried all the things I could think of -- tightening screws and bolts,
checking  for items on walls, tables, etc. ;  checking the soundboard under
the plate with a mirror;  voicing the hammers;  exchanging the problem
hammers with others;  de-tuning the notes so there were very obvious beats
( which didn't bother her).   I asked another technician in to try and find
the problem, with no luck.  She still hears the noise, but has decided she
will have to live with it.

Now the next step.  I tuned the piano a few days ago, and noticed a noise I
don't recall hearing before.  (Which doesn't mean it wasn't there.) This
noise was quite evident when playing notes from the D3 area to the  top of
the piano,  although  the noise was stronger with some notes than others.
I find words rather inadequate when trying to describe a sound, but that's
all we have to use.  I would not use the term rattle -- perhaps a metallic
buzz.  Or metallic "shimmer".   It reminded me very much of the sound a
cymbal with rivets makes as the cymbal reaches the end of its decay.    I
also discovered when I bumped the pins in the high treble section with my
hammer that the same noise was produced.  Or a light tap on the plate strut
next to the pin block would also make the same noise, so the noise isn't
caused by any of the tone producing parts of the piano.    No coins, pens,
nails, hammers, or objects on the plate.  Does know the cause and a
solution?

Thanks.

Don Price, RPT
dcp@sosinc.net