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Your point about whole wire size changes is well taken, but it really applies only to the lowest part of the tenor bridge and then only when the bridge has been foreshortened a fair amount. The rest of the scale is generally better off using half-sizes.

Originally posted by BDB:
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I suspect that problems with what people characterize as the "killer octave" may be the result of bad scaling in that area. As you can see in the top graph, the tension was extremely high in that area, meaning the strings were very thick for their length. That cannot be good.

This piano has the original soundboard and bridge, about 80 years old. The work was done on-site, eliminating moving costs. The question of the effect of soundboard design on sound is much more difficult. Rescaling takes just a couple of hours to measure the speaking length and stare at the numbers to come up with something reasonable. That is cheap enough to do even for a small improvement. Replacing the soundboard would double the cost of restoration with no guarantee that there will be a significant improvement. That makes no sense.

Originally posted by BDB:
No, I have not delved into bass string design. Again, too many factors to be certain of the results. For the most part, the bass string manufacturers know their business fairly well, often better than the piano designers.

Soundboard replacement—when necessary—does solve the problem and the results are quite predictable. Assuming the shop doing the replacement knows what it is doing, of course.

Most string winders, such as Mapes, follow factory specifications pretty closely.

FAQ's about Sanderson Accu-Strings


I have a Steinway O ( or some other piano), do I need to measure the piano to order replacement strings? Easily the most commonly asked question, and the answer is yes. In a perfect world, the same model of piano from the same manufacturer would have the same measurements. However, even the finest piano models vary from piano to piano with regard to speaking length. This variance is enough to drastically effect the sound quality if the wrong measurements are used. To get the best possible sound, we design and manufacture our strings using measurements taken from YOUR piano, not someone else's. (A fine example would be the Mason & Hamlin AA, which varies by as much as 1.5 centimeters in the bass speaking lengths, even for the same model year.)

Why rescale my piano? If your piano has been rebuilt it has already been inadvertently rescaled. Present methods of string duplication make it virtually impossible to get strings remade to the manufacturer's original specification. We rescale to our original aural and mathematical standards to give you an optimum set of new bass strings.

Was my scale perfect? The original scale was done by trial and error prior to the days of computer enhancement. Depending on the manufacturer and model, the amount of attention to scale design varied greatly. Some old scales are in fact virtually perfect, but most can be improved.

Can a computer generate a perfect scale? While the beauty of a scale is determined by ear, duplication of that beauty can be translated from piano to piano by today's formulations. We can define the parameters of good piano sound, the proper mixture of tension and inharmonicity, thus finding each note's "sweet spot".

Does good sound have a mathematical component? Superb piano sound, mathematically speaking, is a balance between string tension and inharmonicity. Mathematics helps us arrive at the optimum values for each of these by helping us choose the ideal core wire size (inharmonicity), and the ideal copper build-up (tension). Both of these values are calculated to match the note's speaking length.

What about the bare lengths? The bare lengths (the core wire in the speaking section which has no copper) are a critical factor in the string's inharmonicity. Typically, with each replacement set of bass strings, a string winder will increase these bare lengths as a "margin of safety". By a second rebuild, the string winders hay have added over an inch of unwanted bare length to each string at both ends. They do this to insure that your new strings will fit, unaware of the disastrous effect on the piano's inharmonicity.

What about the different sizes of wire and wrap? It is essential for the best results in string design that the string winder have all of the size options for both copper and steel wire. Few string winders have all of the size options for both copper and steel wire. We do! If the string winder does not have all of the sizes, then he must redesign and substitute. Is this the right way to get the best job possible?

Will rescaling solve my tonal problems? Properly scaled and accurately constructed strings will sound great! Learn to ask, "Do these strings have a pleasant sound?" After all, what else should be the ultimate test? If a bass string does not pass this test, even on a light blow, then something is wrong with that string and it should be replaced. That's the only cure. We guarantee our strings will sound great.

Originally posted by BDB:

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Soundboard replacement—when necessary—does solve the problem and the results are quite predictable. Assuming the shop doing the replacement knows what it is doing, of course.

I suspect that almost everyone who replaces soundboards knows nothing about the design of them, and just replaces with a copy of the original. How many people do you think there are in the world who could do otherwise? (And do they agree on the solution?)

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Most string winders, such as Mapes, follow factory specifications pretty closely.

I suspect that they follow industry standards. However, factory specifications are not likely to be available for enough pianos that they would have to be able to design strings on their own very quickly.

Originally posted by Jan-Erik:
The soundboard is the soul the piano (Vincent Chavanne). I have heard that the result soundboard replacement is very hard to predict.

Originally posted by BDB:
I was not asking about replacing soundboards per se. I was asking about people who can redesign and replace soundboards. It sounds like your shop could well be the only one in the US that can redesign a soundboard, Del.