No downbearing ? REVISITED

[David Skolnik]

---------------------- multipart/alternative attachment
John,

First of all, I suspect my use of  the phrase "unintentionally misleading" 
may have seemed too provocative. I didn't mean to imply that you are 
mistaken, intentionally or not, nor was it my intention to personalize my 
comments, thereby placing the burden of my education upon you.  However, as 
I reread my previous posts, as well as the responses, I feel my questions 
continue to be valid, and remain unanswered, and that there is a  tendency 
to talk past one other.

I am NOT a rebuilder. My concerns are both more immediate and, at the same 
time, more theoretical. I don't need to know what the board was doing 
before stringing, nor do I need to know what it might do if and when I 
de-string it.  I want to understand how the available measurements  relate 
to the aural performance of the piano, and I want to know that these 
measurements are accurately reflecting the physical conditions before 
me.  I do believe it is possible to measure this "distance" bearing, as 
Isaac Sur Noos called it.

Most responses, sooner or later, tend to re-form the discussion either into 
rebuilding issues, ie. compression vs. rib crowning; preferred method of 
setting downbearing; soundboard impedance; or else venture into the 
pragmatia of experience...pianos which sound good in spite of anomalous 
measurements, thus proving the irrelevance of the traditional 
parameters.  These anomalous measurements are such if 1) you believe that 
some sort of discernable (readable) downbearing should exist, and 2) you 
have a reliable way of measuring that downbearing.

John, you said the following:

>If a piano has no down bearing the vibrations of the strings will still 
>find their way into the soundboard.

This is, of course, true, but this doesn't mean, nor do you say, that said 
delivery of energy will be efficient, optimal and undistorted.

and also:

>People often have the wrong notion that down bearing helps to get the 
>vibrations into the soundboard by the simple act of pressing the string 
>down on the bridge, as if that force would help to make a better 
>connection - like some sort of electrical connection.

The following are 2 excerpts from the Wapin patent:

>>As is commonly known in the art, bearing point edge...and first bridge 
>>pin ... preferably cooperate in defining the second terminus of a 
>>string's speaking length.

and

>>...maintaining the down and sidebearing condition of each string against 
>>bridge face ... and first and second bridge pins ... can aid in the 
>>transmission of each string's vibrational energy to the bridge structure 
>>and soundboard

Now, just because such a claim is made in a patent application does not 
make it so, but it would seem to suggest, to some degree, the view that 
downbearing does have an impact on energy transmission.

John, you said:
>  I was pointing out that down bearing is an indirect effect. Down bearing 
> is one of many factors that control the rate at which the vibrations in 
> the string will flow into the soundboard. It does this by altering the 
> impedance of the soundboard in relation to the vibrating string. It is 
> not a note by note or a string by strings effect. (Italics are mine - DS)

So I think you are saying that having zero or negative downbearing should 
have no detrimental effect on the quality of an individual note. Do I have 
that right?  I guess I would wonder then how many notes, how large a 
section would it take for zero or negative downbearing to have a 
discernable impact?  Or to borrow a term from the sculptor Richard Serra, 
how "site-specific" is impedance?


>So I stand by my statement that down bearing is not necessary in order 
>have the vibrations in the string transfer into the soundboard. And 
>Jean-Jacques is right in saying that "the mere "grip" that the string has 
>on the bridge being sufficient to assure this transfer." That grip 
>provided by the side bearing of the strings through the staggered bridge pins.

My point is that, while I believe you are making what might be a 
theoretically correct statement regarding the transfer of vibrational 
energy from string to board, your words can be taken to condone a vast army 
of poorly executed piano construction and reconstruction out there,

Is it fair to ask how much negative downbearing you would allow on one of 
your pianos?

Please rest assured, I won't do it on Monday!


Regards

David Skolnik RPT


---------------------- multipart/alternative attachment
An HTML attachment was scrubbed...
URL: https://www.moypiano.com/ptg/pianotech.php/attachments/68/8b/d4/db/attachment.htm

---------------------- multipart/alternative attachment--