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Building a dreadnaught and thicknessing the top braces by hand. one of the x-braces is a very small amount thinner than the other (this is also true on a few of the finger braces). I'm talking .012 inch difference in the finger braces and .024 inch difference in the x-braces.

My question is not if this is ok but what side (base or treble) would you put the thinner braces on? I have read a few thing about scalloping more on one side vs the other but can't remember many details about the theory.

Thanks

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Bro. Matthew A.
Oklahoma

I would put the thinner one on the bass side. That's the side to scallop for better sound as well.

what is the size of the braces? The finger braces are not that critical .

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

I don't have the plans on me right now (they are at work) but I believe they are 5/16(.3125)....it's what ever the herringbone dread plans are. the thinner one is about .295ish.

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Bro. Matthew A.
Oklahoma

I would use it but make them the same if you can. I wouldn't scallop them at this point. If you have on brace much smaller than the other you can create an imbalance and may have more bass or treble than you would want.
There is a misconception that early builders will think that making a top more flexible will make it better . If that were the case we would be bracing paper . If you are building a "martin" style you may want to redo the braces for the full 5/16.

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

I would but I don't think I have enough bracewood left. all my bracing is red spruce and I do have some sitka but that may be weird to have one x-brace red and one sitka. What I had in mind was to put the wider one on bottom and the thinner one on top. OR would you advise thinning the 5/16th one down to equal the thinner one?

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Bro. Matthew A.
Oklahoma

make them equal thickness

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

They should be fine. The height makes a lot more difference than the width.

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Ken Franklin
clumsy yet persistent
https://www.kenfranklinukulele.com

I am really intersted in that reply and wonder if any builders deliberately carve one side of the X brace more than the other. In some ways it seems Bizarre to have total symmetry in the X brace given the differences in frequency and tnsion that are going on above it.....
hope that isnt a Hi jack

Not hi-jacking at all!! here is a picture of what I remember reading some time back that I found



Interesting...

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Bro. Matthew A.
Oklahoma

First: acoustically there is no 'bass side' or 'treble side'. The low notes come off the whole lower bout as it vibrates like a speaker cone and pumps air through the soundhole, and at higher frequencies the top breaks up into patterns of smaller and smaller active areas that vibrate out of phase with the ones around them. The bracing influences the shapes of those areas, but they're all over the top.

There has been a lot of discussion in the guitars acoustics literature about whether symmetric or asymmetric bracing is 'better'. It seems to me as though symmetric bracing tends to reduce losses as the top vibrates. However, in the mid-range, where the top is split into two areas that are out of phase with each other, asymmetric bracing might be more effective at actually producing sound. Having done a 'matched pair' experiment on it, I've gone to using symmetric bracing, but the difference is not huge. Asymmetric bracing does seem to impart a 'characteristic' sound, and some people prefer it for some kinds of music.

Sitka and Red spruce tend to have about the same density and Young's modulus along the grain: that's why they used Sitka in the aircraft industry when the Red ran low in WW II. However, they both vary a lot in density, and the Young's modulus tracks that. If your Sitka has about the same density as the Red, I would not worry about substituting one for the other for bracing. If the density is much different, you could end up making more of a change that way than you would by using the thinner braces. As has been said, height matters more than width anyway.

I carve the lower legs of the x brace to free up the lower bout for a better lower fundamental to support the note at the open E string.most guitars are lacking the lower fundamental responce because of this area being too stiff.That is why most open A strings sound better on most guitars.On dreads, i scallop the bass side to help with this inherent problem.

If you cap your X-braces what dia. do you use if you are using .030 for thickness?

Chuck

I think there are a few builders who vary the dimensions of their X-Braces.

Check out the Single Scalloped X Bracing in "Guitar Details" that this well known builder uses on Dreads...Rumour has it he knows his stuff

http://www.pantheonguitars.com/

Ray

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Guitar Building = Continuous Improvement Process