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Old 01-19-2021, 08:08 PM
yellowesty yellowesty is offline
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Join Date: May 2016
Location: Petaluma, California
Posts: 168

As long as all the elements (the braces and the soundboard, in this case) are operating in their linear mode (stress proportional to strain), then gluing a contoured brace to the soundboard using a flat gluing caul won't change the overall stiffness.

The resulting soundboard (and contoured brace) shape will be that which equalizes the strains in the two elements. That will result in a shape which is less pronounced than the original brace shape and will lock opposing strains into both elements.

It sounds like a bad idea. Any environmental change (temperature, humidity, aging of the materials, etc.) that changes the stiffness of one element more than the other will rebalance the strains, resulting in a changed shape to the soundboard. That's unlikely to improve playability.

And we most certainly want to construct our musical instruments such that the components function in a linear mode. Otherwise, the instrument will, itself, create anharmonic (aka dissonant) sounds (don't call them "harmonics," they won't be).

On a similar topic, this is a reason to contour the back of the bridge and the top surface of the bridgeplate to match to soundboard contour. There is no upside in locking unnecessary strains into our builds.

Last edited by yellowesty; 01-19-2021 at 08:12 PM. Reason: elaboration
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