[pianotech] Steinway A Bass String Rescaling

[William Truitt]

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.  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).  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.  

A couple of months ago there was an article in the Journal about bass
scaling.  It's jist was that it is desirable to lower the bass
inharmonicity, at least to the level that we would see in a concert grand.
Interestingly, the author gave no clue as to how he went about rescaling the
bass strings to achieve the desired values.

I understand that a piano that has little or no inharmonicity would be
pretty milque toast.  Still, the question remains:  Given the physical
limitations (as in the laws of physics) of a particular sized piano with a
given string length for Note (fill blank), what is a desirable and
appropriate range, how do we determine that, and what manipulations would we
engage in to achieve that?  Since my discussion was about the scaling of a
6' 1" Steinway A, we can use that if we need to narrow things a bit.

Thanks for your comments.

Will

-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of JUDE REVELY
Sent: Friday, May 22, 2009 8:09 AM
To: pianotech at ptg.org
Subject: Re: [pianotech] Steinway A Bass String Rescaling

As I understand it, there are also things that can be done to the whip to 
allow for increased flexibility at the ends and the ability to use a smaller

diameter core. This was the nature of Dr. Sanderson's last string related 
patent. I believe the Sanderson's call their version an "inharmonicity 
lump," although as Ron states, the benefit is in the smaller core, and the 
inharmonicity is along for the ride. There is a point of diminishing return,

however. Too little inharmonicity in the bass and there will be no tone 
whatsoever. So it is still important to manage the low bass inharmonicity so

that it is within an appropiate range and even from note to note.

Jude Reveley, RPT
Absolute Piano Restoration, LLC
Lowell, Massachusetts
(978) 323-4545

----- Original Message ----- 
From: "Ron Nossaman" <rnossaman at cox.net>
To: <pianotech at ptg.org>
Sent: Thursday, May 21, 2009 9:24 PM
Subject: Re: [pianotech] Steinway A Bass String Rescaling


> William Truitt wrote:
>
>> Those of you on the list who have engaged in bass string rescaling along 
>> these lines, I would most appreciate your comments and your observations 
>> on the aural  benefits derived from such machinations.
>
>
> Getting the rebar cores replaced with something smaller and more flexible,

> like that 0.053" you noted, is a big low bass improvement. Add double 
> wrapping, and you've improved the flexibility of the string enough that 
> there might actually be some fundamental in it instead of a lot of high 
> partial clank. Getting the break% up is then easy because of the smaller 
> diameter core. The inharmonicity decrease is an artifact of these 
> beneficial changes, and is just more or less going along for the ride.
> Ron N
>
>