It is a 1.45m Gaveau of 1910. After months of work his old beauty was back, but the sound was disappointing: dead bass strings, bad transition from bass to midsection with also many nasal tones and sounding much too loud at the end of it. Even so… not the least said: it plays fantastically and looks like a jewel.

It seemed the strings had to be replaced. Before I started with that I did want to know what the old strings did. With tape measure and digital sliding callipers I brought up a picture of all strings. I hoped to get an idea of the quality of the scale by putting those string data in trial versions of existing software. The input was problematical and the output of that software could not convince me. It produced numbers indeed, but the significance and the origin of those numbers could not be retrieved. The most annoying thing was the fact that with that software no clarity was obtained about the original scale because they operated with the only steel wire the programmer had put down.

That could be done in a better way. On the site of Pure Sound I found data of old en new steel wire. The formulas for the calculation of string tension were easily found, those for the frequencies took more research and when I wanted to calculate inharmonicity I entered a dark world. My first finding was the little book of W.T. Goddard. It made me glad, but his formula for the inharmonicity of the bass strings gave strange results  in my spreadsheets. Continued searching got me on Fletcher and Rossing, who recommended the formula of Sanderson. I used that and I calculated a new scale with Pure Sound wire. The new strings gave the Gaveau a sound that matches its appearance: splendid!

From my contacts with Juan Más Cabré, the supplier of Pure Sound wire, it became clear that the need exists for a program to adapt existing scales to his steel wire. I decided to convert my spreadsheet into an easy to use application. The consequences were drastic!
The applied formulas had to stand the test of criticism. Those for the wound bass strings bit the dust. To meet the needs for my application its action is limited to the plain steel strings, where the influence of the applied steel wire is obvious. Calculation of wound bass strings depends less on the characteristics of the core wire. I have postponed that till close examination has delivered correct formulas.