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I visited a professional guitar builder who places x braces below the bridge. He does not radius the top braces. His tops are completely flat, and he feels the location of the x bracing keeps the top flat. Unfortunately, there were only two guitars I could play, an older one he was reselling for a client, and a new one. Both sounded very good. I am starting one I plan to brace this way, but I am concerned about the other brace placement since I could not see his complete bracing pattern. Would like to hear from anyone who has used this type bracing.

Ask Al Carruth ..... or search the archives .. he built two similar guitars a while back, one double X, the other more std bracing style .... interesting comments IIRC ...

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

I built that pair a few years ago; a couple of maple/Sitka small Jumbos. One had 'standard' style bracing, with parallel braces below the X, and the other had 'double-X' bracing. Essentially, the lower tone bar was turned 90 degrees and moved up a little so that it crossed the upper one on the center line. Otherwise the two were as nearly alike as I could make them, with flitch-matched tops and so on.

I took them to the ASIA meeting, and had about 60 luthiers try them out. I didn't tell them what the difference was until after they'd played them, of course. Some of the guesses were pretty interesting.

The outcome was interesting, too. Basically, there was about a 2 to 1 preference for the double-X braced top, but it was small: most people liked it a little better. Several folks said that the 'normal' guitar sounded more 'traditional', while the double-X was more 'modern'. The preference was a bit stronger when the test was conducted in a place (the school lobby) where you could hear them better, rather than in the exhibition hall, which was noisier.

Both were good guitars. The difference was not huge. Basically, I look at it as another weapon in the arsenal, as it were: a certain kind of control that I can use when I want a particular sound.

I am pretty much using a very light lattice in the lower bout on all of my guitars now. I like it.

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

I don't think the bracing was a double X. At least a double X was not mentioned.

Well, I don`t know if this helps, but I had the idea of trying a X under the bridge plate as well. This guitar is a Baritone. After having read a few interesting threads regarding keeping the inside of the guitar clinically 'clean', I decided to keep this one rough... Glue squeeze-out, pencil marks (not that that should make a difference)... I even scuffed the whole inside of the guitar with 100 grit... I did it on purpose! Really!!! LOL

Since this was my first Baritone and my first attempt at a double X, I have absolutely no idea if it accomplished anything. It does sound great, if I do say so myself and has held up well under tension for the last year or so, considering the long scale lenght (29.0) and all the movement associated with lightly built custom guitars...

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I'd like to be able to prove, just for once, that money wouldn't make me happy...

That is what I think of when I hear someone say a double X. much more beefy and restrictive (imo) than a somewhat smaller cross brace like above, or even one step further and a very small lattice work.

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John Mayes
http://www.mayesluthier.com

Or like this.....


I'll tell you how it sounds in a few months....

Thanks

John

I always assumed that having a structure such as a second Xbrace below the main Xbrace would be detrimental or constricting to tone, maybe just from my experience playing larivee guitars, which have a lateral brace going accross the lower half of the X brace. That is not to say that larivees sound at all bad, but they always had a little bit of a tighter sound that I didn't look for in a guitar, but I am interested to hear how the double X braced guitar would sound, especially if it would have some structural benefits as well.

John, I like the look of your design, and I like how you did not butt the smaller X brace against the main Xbrace. I assume you did this in consideration for not making the stucture too strong. Did you radius the smaller Xbrace?

There's no particular reason why the double-X configuration should be any more 'beefy' or 'constricting' than any other. It's all in how you do it. Gibson, of course, could screw up boiling water...

Not my design nor a guitar I built. It is a C-Fox guitar from when Charles had the small factory going. I don't know the details of such. I've played quite a few of them, but never built one.

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John Mayes
http://www.mayesluthier.com

Totally agree, however it's just what I think of....... Thanks Gibson.

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John Mayes
http://www.mayesluthier.com

x-brace below the bridge would imply a double x style bracing. I have done it and was quite pleased with the tone. It's only tight if your double x is huge.

A couple of things I have found with this is that coupling the legs of the secondary system to the bridge plate makes a BIG difference. And the second thing is it is easy to get this too heavy. You can go very light in that lower bout.

Mine is more of a lattice, but the same general idea applies. Here is more or less what I am doing now.

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

Brock,

Why the two finger braces so close together?

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Jim Kirby
kirby@udel.edu

I am not sure I can really pin down "Structural Benefits" -- it's just an experiment I am trying out.... If you do some math -- you can convince yourself that the wood in the Lower Bout is really there to help control bridge rotation rather than tension.... but in that case, it seems like having light bracing that is reasonably well thought out will spread the force across the lower bout... (I can't say whether mine fits this bill or not ... Time will tell)

In my mind, the key to the whole thing is making the lower X light and willowy enough so it doesn't mess up things... because Lattices have a tremendous amount of strength by their nature of spreading out forces....

As to whether or not de-coupling the lower X from the main X is a good idea... Well -- Time will tell.... I did something similar with conventional tone bars, and it came out quite nicely... My experiment this time was to make the bracing slightly more "Loose" in the center... Seems that I read something somewhere or another that it might be a good idea....

But.. Reading Brock's comments makes me want to try out another one with overlapped and coupled Lower X -- just even lighter than this one... I am thinking the obvious benefit is that it would spread out the "Belly" more evenly across the whole lower bout -- which seems to also be a good thing...

On curving the bracing -- yes, I sanded all the braces into a radius dish before I glued them on.

Now, if I can only get it finished up before Christmas....

Thanks

John

Stiffens up the wings to the torque of the bridge, it looks like to me. Not that I know what I'm talking about!

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Actually what I am doing with the finger braces is trying to tie them into the bridge. I only partially look at the braces as structural members, and partially as conduits for the energy of the bridge. I think that is why I have found that coupling the lattice to the bridge plate makes such a big difference.

Why one finger brace vs. two? I find that I get better clarity with two. Structurally, one works. But I think I get a sound improvement with two.

YMMV.

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com

So far as nomenclature, I'd call this a 4X pattern, with diagonals crossing the main X and each other below the X. What I'd call double X has the diagonals not crossing the main X.

It looks like an overly stiff design, to my eye. Doesn't let the wings of the bridge move.

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Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

I suppose from a technical standpoint you'd be correct.

I was thinking more in a two x-braces offset and interlocked.... which it is, but as you pointed out there are more than two x intersections.

I agree on the overly stiff design. These are not my design. It's a shot of a C-Fox guitar when Charles had the little factory going. I've played a few of them and they sounded stiff too. Of course many people loved them so it's all relative.

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John Mayes
http://www.mayesluthier.com

Considering the pull on the bridge, why not have larger, or heavier x brace below the bridge. Isn't the whole idea of the x brace to prevent the pull on the bridge to stop it from bellying up? Seem it would be stronger than the x above the bridge. As to the sound, that is another question.

No, not really. It is certainly part of the purpose for the brace but not all of it. Most production guitars are massively over built (and I understand why) and I think you will find you can lighten up quite a bit without any serious negative effects. (But all things in moderation).

With respect to the bellying. I don't see that as a problem as long as it is just a little.

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Brock Poling
Columbus, Ohio
http://www.polingguitars.com