[pianotech] Steinway A Bass String Rescaling

[William Truitt]

Hi Ron:

I am not afraid to expose the limits of my understanding, and I have done
just that, as you so kindly point out :-)  

You ask:  Why does the inharmonicity in the low bass have to be higher than
the lowest point of the curve? (Which is usually represented at the bass
tenor break).  I don't know.  That is something we generally see in the
scaling programs, and I have never seen an explaination of why that must be
so.  Nor do I know what limits there are that would necessarily make it so.
But since you ask the question, what kind of inharmonicity curve do you
desire, and how much of it is achievable?  Since scaling is always a set of
trade-offs, where do your priorities fall and in what order?  

As for your concept alert, I would say this:  Smoothing and blending the
curves of an existing scale does improve it, and makes it better at what it
already is.  This ongoing discussion is furthering my understanding of ways
in which we can alter the scale to improve it - in this case, decreasing
core wire size,amongst other things.  And in this case, I have the advantage
of hearing a rescaling that is audibly significantly better than the
original, and I can match numbers with what I am hearing in a real piano.  

Will

-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Ron Nossaman
Sent: Friday, May 22, 2009 9:53 PM
To: pianotech at ptg.org
Subject: Re: [pianotech] Steinway A Bass String Rescaling

William Truitt wrote:
> Hi Jude:
> 
> I have rescaled a number of pianos in the past, and I have always wondered
> what the inharmonicity numbers really mean.  I know they are supposed to
> fall in the hockey stick on the graph, but really I have nothing for them
to
> stand in comparison to.  

Are they? Why does the inharmonicity in the low bass have to 
be higher than the lowest point of the curve? Since I've 
gotten into scaling, I've wondered why so much emphasis is put 
on inharmonicity, when it's functionally of a relatively low 
priority other than big jumps at breaks.


>Typically in the past, I have aimed to even out the
> inharmonicity and the tensions (with attention paid to breaking
percentage)
> as much as possible without taking the scale in another direction (i. e.
> making the scale better at what it already is).  

Concept alert! I thought the whole point was to make the scale 
better than it is.


>What is interesting about
> the present discussion is that we are moving the general parameters, as
well
> as working to achieve evenness through the scale.

Well, yea. The intent is to improve the thing.


> I understand that a piano that has little or no inharmonicity would be
> pretty milque toast.  

Maybe, but is it achievable in the real world for testing?
Ron N