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Old 12-14-2020, 06:58 AM
mhw48 mhw48 is offline
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Join Date: Mar 2018
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Quote:
Originally Posted by Alan Carruth View Post
Chladni patterns are simply a 'tech' version of 'tap tone' tuning, with the advantage that you get to see the patterns of the resonances. The shapes of the vibration modes gives information about the way mass and stiffness are distributed in the plate, while the pitch is related to the overall ratio of stiffness to weight. Looking at the pitch of a given mode, then, can enable you to get the top to the 'right' thickness; stiff enough to hold up under string tension, and light enough to work well with the limited horsepower.

Looking at the mode shapes can tell you where to remove wood from the plate or the braces to get everything into balance, so to speak, so that the whole top is working well. You can get much of this information from tap tones, but it takes a lot of practice, and it's hard to communicate with other makers. There are also cases where you might not hear something in the tap tone that you'd see in Chladni patterns: the patterns give you more information to work with.

OTOH, tap tone tuning goes very quickly when you know how to do it. I spend hours sometimes tuning the top for a guitar using Chladni patterns, while Dana Bourgeois can tap tune one in a few minutes. There's no one 'right' way to do it; there's just the way that works best for you.
Thanks for a very readable and concise explanation.
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