Series of tap tests closed through strung on Falcate Classical

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johnparchem
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Series of tap tests closed through strung on Falcate Classical

Post by johnparchem » Sat Oct 08, 2016 7:18 am

I just strung up a falcate classical guitar, viewtopic.php?f=1&t=7444. I have been tap testing the body at various stages and I though some might like to see the changes through process. The changes, closed to bound - to with bridge - to strung, are pretty typical of what I see on a falcate classical guitar. On my classical guitars, the addition of the bridge raises the T(1,1)2 6-9 Hz, it always drops on my falcate steel string guitars when I add the bridge. Also one can clearly see the coupling between the resonances through the process. My T(1,1)2 target is 190 Hz, At this point I am at 194 Hz strung up. The back is high at 159 Hz, and it does not really have that big of a peak. I will start shaving the back braces, until I either hit 4 semi tones or the top hits 190 Hz.


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The first is the body closed before routing for the bindings.
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The Second is with the binding and the guitar has finish.
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Here is the guitar after the bridge is glued on
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And with strings
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seeaxe
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Re: Series of tap tests closed through strung on Falcate Classical

Post by seeaxe » Sat Oct 08, 2016 6:18 pm

Hi John
Thanks for posting these, I am sure I will find them useful as I move forward through the next builds.
Interesting that the top resonance goes up when you add the bridge. I guess the increase in stiffness offsets the additional mass.

Cheers
Richard

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kiwigeo
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Re: Series of tap tests closed through strung on Falcate Classical

Post by kiwigeo » Sat Oct 08, 2016 10:19 pm

seeaxe wrote:Hi John
Thanks for posting these, I am sure I will find them useful as I move forward through the next builds.
Interesting that the top resonance goes up when you add the bridge. I guess the increase in stiffness offsets the additional mass.

Cheers
Richard, you've hit the nail in the head. With a Gore style classical you wouldn't normally have a bridge patch...ie all the stiffness is in the bridge with it's two layers of CF. With a Gore style steel string there's a layer of CF plus the bridge plate under the bridge as well as a layer of CF in the bridge hence the effect of bridge mass is greater than stiffness.
Martin

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