Using The Scale Calculators

The Scale Calculators can be used to do a basic scale evaluation with the following procedure:

Step 1:    [ Return to Free Page ]

Measure speaking length and wire diameters for the following notes:
lowest bichord on bass bridge
highest bichord or trichord on bass bridge
lowest plain wire note
a plain wire note in lower treble
note 88

Bass strings require:

note number
speaking length in millimeters [SPLM]
core diameter in decimal inches [DIAM]
outside diameter of copper wrap in decimal inches [ODWRAP]
length of exposed core at ends   i.e. (agraffe end + bridge end) / 2   [ENDS]

Plain wires require:

note number
speaking length in millimeters [SPLM]
wire diameter in decimal inches [DIAM]

Step 2:

Print  out the Tension / Inharmonicity Chart (load the page, click File, then Print)

Step 3:

Load the Bass String Calculator or Plain Wire Calculator, enter your data values, and manually plot the tension and inharmonicity values on the chart. You will notice that it is difficult to do this with very much accuracy but even approximate locations will give you enough to evaluate the scale. The hockey stick lines are general inharmonicity guidelines and reference the left side numeric values. The three pairs of horizontal lines are general tension guidelines and reference the right side numeric values (or left side*100). The left pair = unichords, middle pair = bichords, and right pair = trichords. These guidelines are general and only apply to pianos up to about 7' in length.


I theory, one could use these calculators to actually redesign a scale. However, it would prove to be a long and arduous task. I strongly recommend PSCALE as the real time graphics, automatic bass scaling, and many additional features streamline most scaling procedures. There are currently hundreds of PSCALE users who would agree.

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