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What is double X bracing and does anyone have photos?
thanks
-j.

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“If God dwells inside us like some people say, I sure hope He likes enchiladas, because that's what He's getting”
-jack handy

I have seen some on the site. but in simple terms it is replacing traditional tone bars with a second x-brace below the bridge plate.

Avalon guitars uses this bracing design, and if you don't like ringing harmonics and lingering sustain, don't do it!!!

I've play an Avalon, and I know what the tone is like.. Sam Price38975.4484143518

I usually use a double X on my fingerstyle instruments, especially on cedar and redwood tops because it gives good support behind the bridge where the top usually bellys up. I have been very happy with the sound with this pattern. My finger braces are not part of the lower X the way Sam's are. I don't know what difference that would make in the sound, I have seen it done both ways.

                    Peace, Paul

J, I was looking for and image of my double x tops but I'm in the middle of switching computers and can't find a thing. It looks almost exactly like the one Sam posted.
I build double x tops exclusively for two years. I've since moved away from them and am building with a standard finger brace design. I found that the double x was great for a strummer and even better for someone with a heavy hand. But I found that it tightened up the top too much for a light touch and finger picker. So, in my opinion, it tightens up the to a little too much.

Paul,
I would think that it would tighten up the top a lot unless you shave them down to almost nothing.
This, is however, going to be for a bass and a baritone guitar, so the tensions are going to add significantly more stress to the top.
I was thinking the double X brace would be more efficient than beefing up the typical single x brace and tone bars. Does that sound right?
-j.

_________________
“If God dwells inside us like some people say, I sure hope He likes enchiladas, because that's what He's getting”
-jack handy

Well, yes, it did tighten the top a lot but I guess I was thinking "a bit" too much for my tastes. I did shave them much lower that the main x but still couldn't get it to open up the way I wanted it to.
I think it will be a great option for long scale, high tension instruments.
Be mindful of where the bridge will be when you lay it out. You don't want bridge pins going through braces.

No pictures.....but mine looked almost exactly like Paul's picture. I used a double "X" top on my last guitar and it sounded great both strumming and fingerstyle. I felt it was better in all respects compared to the traditional "X" bracing used on the previous one. Different B/S woods may have contributed to tonal differences as well, so take the opinion FWIW.

Greg

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Gwaltney Guitars

[QUOTE=j.Brown] Paul,
I would think that it would tighten up the top a lot unless you shave them down to almost nothing.
This, is however, going to be for a bass and a baritone guitar, so the tensions are going to add significantly more stress to the top.
I was thinking the double X brace would be more efficient than beefing up the typical single x brace and tone bars. Does that sound right?
-j.[/QUOTE]

J,

I don't know about bass guitars but a baritone guitar should have the same string tension as a normal scale guitar if designed properly. You don't want to be beefing up the braces at all.

By the way here's a pic of my baritone bracing which happens to be a sort of variant of the double X but with the bottom X bar "broken":

Dave White38975.6579861111

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Dave White
De Faoite Stringed Instruments
". . . the one thing a machine just can't do is give you character and personalities and sometimes that comes with flaws, but it always comes with humanity" Monty Don talking about hand weaving, "Mastercrafts", Weaving, BBC March 2010

Dave, Thats what I originally thought, but according to the D'Addario website, the baritone string tension adds up to almost 240 lbs total of tension. Thats a heckuva lot more than the typical 5 string tension of 160-180 lbs.Thats an increase in stress of almost 50%.
Maybe its not reality or something, but its right on the companies spec sheets.
http://www.daddario.com/Resources/JDCDAD/images/tension_char t.pdf http://www.daddario.com/Resources/JDCDAD/images/tension_char t.pdf
Let me know if I'm reading these incorrectly.
Specifically the EXP 23's for a baritone string.
Thanks
-j.
-j.

_________________
“If God dwells inside us like some people say, I sure hope He likes enchiladas, because that's what He's getting”
-jack handy

J,

If you want to put those gauge of strings on then so be it, but my contention is that you don't need to. For B-B tuning on my 28.9" scale baritone I recommend string gauges of 0.014", 0.018" (or 0.023"w), 0.030", 0.039", 0.047", 0.065" (0r 0.070"). These are D'Addario EJ15's with the first string removed and an 0.070" added. This gives great tone and volume on the guitars I build. The string tension is pretty close to inbetween a set of EJ16's and EJ17's on a 25.5" scale length guitar in standard tuning.

Even if you go for the heavier sets and 230lbs plus tension I would not beef up the bracing - same arguments as for making a 12 string. I recently made a 10 string guitar-cittern with 230lb string tension and the bracing height and profile etc were as per normal. Sounds wonderful. I would pay a lot of attention, however, to keeping the bridge on under such tension and also long term neck stability.

I suspect I am in the minority of baritone builders with my views here, but hey variety is the spice of life. The proof of the pudding is in what I hear from the guitars I have made. I have a recording of my euro spruce/braz rw bari on my website here. Go to Treebeard on the page.

_________________
Dave White
De Faoite Stringed Instruments
". . . the one thing a machine just can't do is give you character and personalities and sometimes that comes with flaws, but it always comes with humanity" Monty Don talking about hand weaving, "Mastercrafts", Weaving, BBC March 2010

[QUOTE=j.Brown] Dave, Thats what I originally thought, but according to the D'Addario website, the baritone string tension adds up to almost 240 lbs total of tension. Thats a heckuva lot more than the typical 5 string tension of 160-180 lbs.Thats an increase in stress of almost 50%.
Maybe its not reality or something, but its right on the companies spec sheets.
[/QUOTE]

I think you might have done something wrong - either that or I'm messed up.

I ran through the calculations. Here is what I found based on that site and doing the calcs.

Increasing from a 25.5 to a 27.5 scale length, keeping the same diameter string at the same pitch increased tension 16.3%.

Increasing from a 25.5 to a 27.5 scale length, keeping the same diameter string dropping pitch 1 whole step decreased tension 7.6%.

I think you messed up in reading the chart - you can't do that for a baritone because the tension on the chart is calculated on a 25.5" scale length. To get the tension for a baritone, you have to do the calculations.

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"An adventure is only an inconvenience rightly considered. An inconvenience is an adventure wrongly considered." G. K. Chesterton.

I did an experiment comparing 'regular' and 'double X' braced tops on two 'matched' guitars a few years ago. The bracing was the same size on both instruments, just placed differently. At the ASIA meeting that year the luthiers prefered the double-X topped guitar by a significant margin. Most people though the double X would be beetter for fingerstyle. It can work if you do it right.

I double-x brace my backs-sometimes. I like it. I think it makes it easier to tune the back.:

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Dave Bland

remember...

"If it doesn't play in tune...it's just pretty wood"

Dude, those are some sweet clamps! Where ja git em?

Speaking of clamps.... Paul, i think you're do for some more!

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Peter M.
Cornerstone Guitars
http://www.cornerstoneukes.com

Is that a white Hiscox case Dave?

Colin

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I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

[QUOTE=Colin S] Is that a white Hiscox case Dave?

Colin[/QUOTE]

Colin,

Yes - well ivory actually. They do them in all sorts of colours now.

_________________
Dave White
De Faoite Stringed Instruments
". . . the one thing a machine just can't do is give you character and personalities and sometimes that comes with flaws, but it always comes with humanity" Monty Don talking about hand weaving, "Mastercrafts", Weaving, BBC March 2010