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Ring & a Half Mode: Before and After Bracing
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=23598		 Page 1 of 1
Author:  Darryl Young [ Thu Aug 27, 2009 9:25 pm ]
Post subject:  Ring & a Half Mode: Before and After Bracing
I was curious how the bracing would change the ring & a half mode on my soundboard both in shape and in pitch. I have the braces glued on now so I did a quick test. The "after" photo is after bracing but before I've started voicing. The frequency of this mode raised exactly 100Hz after bracing.....wasn't trying for this and didn't realize this was the case till making this post.

The bracing is Red Spruce and the top is Carpathian. The bracing is traditional Martin X bracing glued with fish glue and the body is an OM. Be interesting to see how the pattern changes and lowers pitch as I shave the braces.

Before bracing, 163Hz:
Attachment:
163Hz1.JPG


After bracing, 263 Hz:
Attachment:
263 Hz After Bracing Before Voicing No Flash.JPG
Author:  truckjohn [ Thu Aug 27, 2009 9:43 pm ]
Post subject:  Re: Ring & a Half Mode: Before and After Bracing
Daryl,

What sort of hardware/software are you using?

Thanks

John
Author:  Darryl Young [ Thu Aug 27, 2009 10:13 pm ]
Post subject:  Re: Ring & a Half Mode: Before and After Bracing
Just an old Dell computer speaker for an amplifier (a cheap one with volume control on the front). I'm using a 4" speaker from an old set of speakers I had in the garage. The frequency generator software I downloaded from the web called PAS (Programmable Analysis Software) for free.

Now that I'm looking at the pics, I sure wish I had rotated the picture 180 degrees before uploading.
Author:  Burton LeGeyt [ Thu Aug 27, 2009 11:21 pm ]
Post subject:  Re: Ring & a Half Mode: Before and After Bracing
Cool! I would love to see how it changes as you start shaping the braces. Thanks for posting the photos!
Author:  Darryl Young [ Fri Aug 28, 2009 1:27 pm ]
Post subject:  Re: Ring & a Half Mode: Before and After Bracing
As soon as I get the chainsaw blade shapened I'll have at it........
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