Soundboard Evaluation

[Baldwin Yamaha Piano Centre]

Hi Terry,
              You need to take 3 measurements with the gauge, speaking length, bridge cap, and back scale.  You can easily get fooled by bridge roll.

Centre the gauge on the speaking length, then the bridge cap should be minus some, and back scale minus some more, if all is healthy.

Rolled or twisted bridges become very apparent this way.  Now you have a real idea of bearing in each section.

The crown is measured with a piece of high tech string. Available from the Jolly supply company at $90US per length.  I feel you should order at least 5 lengths <G>

Roger


>I measured downbearing with my Lowell gauge. The numbers below are the difference in lines on the bubble gauge between the reading on the speaking length segment and the backscale length segment. A positive number means there is positive bearing.
>
>E7   +10
>C7   +7
>A6   +7
>break - G/G#6
>F#6  +6
>E6    +5
>C6    +4
>A5    +2
>F#5  +1
>E5    -1/2
>D#5  -2
>break - C#5/D5
>C5    -2
>A4    -1
>E4    -3