Harmonic Distortion / Overdriving strings?? Noise Question???

[Jon Page]

Last month I tuned a mid 70's S&S M That had something similar.
The only way I though to express it was "ghost wolf".
Maybe the bridge pins are loose.  Very annoying. 

Jon Page

At 06:48 PM 3/6/99 -0500, you wrote:
>Hi All,
>
>I've run into a customer who has noticed a problem with his Boston
>piano.  It's a 6'4" grand.  Playing softly, the tone is good.  But on
>louder playing, and rapid repeated playing of particular notes, there
>comes an irritating sound from the speaking length of the string.  To my
>ear, it sounds like the string is being 'overexcited', or overdriven,
>beyond the point of a clear undistorted vibration.  Kind of reminds me
>of what happens when you overdrive an amplifier and hear the sound
>distort.  On the piano it tends to sound like a zing/ring.  (This is
>like trying to tell a person who has never been sighted what a rainbow
>looks like!)  Upon further examination, I've determined that the 'noise'
>is indeed in the speaking length of the string.  (Blocking out the
>duplex etc. has no real effect.)  Also, I've checked on about a half
>dozen other pianos for the same thing, all the way from Young Chang, to
>Wurlitzer & Baldwin, to Petrof and Steinway.  I was actually able to get
>the same distortions from ALL of them!  The Steinway required the most
>effort on my part to make it give off this 'sound', but I was able to
>get all of them to do it, and over quite a range.  The worst areas on
>most all of them was the range starting about an octave above middle C,
>and continuing up about an octave and a half, but it was indeed possible
>to do this 'overexcitement' over most of the range of the plain wire
>strings.
>
>I've not been able to put my finger on this one.  Some thoughts to date
>are scattered; hammers are too hard, (voicing seems to help a little,
>but it's still there), hammers striking the string in the wrong place,
>(haven't been able to play with this one yet), too much bearing, (I'm
>not sure how too much or too little bearing would affect distortion of
>the sound), poor scale design, (just because it says "Designed by
>Steinway", it doesn't necessarily impress me), poor bridge notching,
>(the notch does not drop away from the string in such a fashion to give
>a good termination point in my opinion, but I don't know what minimums
>would be.  I know I notch mine a lot more deeply and distinctly when I
>do them.)
>
>I just wondered if anybody had a thought.
>
>Thanks in advance.  (And also, thanks for all the good conversation.  I
>just found this list a few weeks ago, and am very happy to be able to
>read the conversations.  I've been learning. (Hope it never ends!)
>
>Brian Trout
>Quarryville, Pa
>  
Jon Page
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I am not an expert, I just play one on the internet.

Dear Lord,
So far today I've done all right. I haven't lost my temper. I haven't 
been greedy, grumpy, nasty, selfish, or overindulgent. For that I am 
thankful. But in a few minutes, Lord, I am going to get out of bed, and 
from then on, I'm probably going to need a lot more help.
Amen


Give a man a fish and he will eat for a day. Teach him how to fish
and he will sit in a boat and drink beer all day.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 

(Rather like the apprentice polisher who, after a day of working on one 
piece of wood, asked the old master how he knew when he was finished with 
a given piece. The answer was: "When they take it away and give me another.")