[pianotech] Steinway A Bass String Rescaling

[William Truitt]

Jude:

So what are the ranges he presented in his handout?  :-)

I am planning on going back to my customer's house and minimally take string
measurements at the end of each section, monochords, bichords, etc., and
perhaps some notes in between.  Then calculate tension, inharmonicity, etc.,
and fill in the blanks by rescaling.  The scale on his piano certainly has
more fundamental than the original scale.  I'm not sure how much the
differences in tension between the two scales ( the original and my
revision) will affect your observation that the cantilevered bridge should
be lightly loaded. I am attracted to this scaling because it is one that I
know sounds really good, and my efforts for the present are to obtain a
deeper understanding of the why and the what.

At any rate, I'll be sharing all that data with you once I complete the
loop. 

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 8:18 PM
To: pianotech at ptg.org
Subject: Re: [pianotech] Steinway A Bass String Rescaling

> Hi Jude,
> Explain, please. Too little inharmonicity by what standard, and arrived at

> how?
>
> Ron N
>

Hi Ron,

Sure, I'll try. Too little inharmonicity by the standard of what is 
generally considered to be good strong fundamental bass tone, and arrived at

according to Dr. Sanderson's formula. I stick to the ranges that he 
originally presented in his handout. I'm not saying it's the Holy Grail but 
that it's a reasonable parameter to observe. Dr. Sanderson did an experiment

where he designed a set of strings with 0 inharmonicity. I was unfortunately

not a primary aural witness to the end result so my "observations" are 
hearsay. So I, too, ask myself, well if this set of strings sounded so bad, 
what were the other factors (T,Z, S, NT/H etc). I'm thinking that I can 
repeat the experiment for a few unisons on one of my own pianos and let my 
own ears be the judge.

Will,

The other factor that I was thinking about today was the load on your bass 
bridges. These cantilevers prefer a particularly light load. I'm finding 
that on a healthy board, you have to set the distance bearing so that the 
string just barely misses contacting the bridge by the time it contacts the 
counterbearing. When the treble bridge is loaded, the bass bridge will rise 
a bit to give you that ever so slight bearing angle. Maybe you can get your 
Wixey gage on it.

Jude