Guitar Making Tip No. 206 is about the X brace. The spread of the X brace has a big effect on the stiffness of the top plate. You can open and close the X brace in relation to the top and bottom of the guitar, and it will make a big difference in the performance of the top. Here is how.
The X Brace Patter for Bracing the Top
Once The Martin Company started using the X brace design, it did not take long for the rest of the guitar making world to follow along. It’s the best design we have so far, and it makes some of the best sounding guitars in the world.
The beauty of the X brace is the ability to spread out the rigidity over the entire top, and overcome the disadvantages of the previous bracing systems. Even being the best, there are still opportunities to tweak the way it works.
The job of the braces is to spread out the forces and tension from the strings. They work together to make the top stiff enough not to bend or break under the force. They also must allow the top to vibrate. Doing these two things at the same time is an art, and the X brace does it extremely well. Here is how you can manipulate your X brace to change the strength of the top…
Close the X Brace for More Strength
When you look at the X brace, with the guitar sitting on the tail and the neck area at the top, you can make the X taller by pushing together the bottom legs. This will also push together the top legs at the same time. The effect is a more narrow X.
With the narrow X, you now have your braces running more parallel to the tension that the strings create. Since the braces run in line with the forces, they counteract them more. This results in a top that is far more rigid.
If you go too far, you can create a top that is too strong, and will need a lot of string tension in order to drive it well. You need some strength, but you also need flexibility. It’s in the flexibility that the top sings, and vibrates to create sound.
Open the X Brace for a Looser Top
Looking at the top in the same manner as before, when you spread the bottom legs apart, you widen the X brace. This means that the wood will be running more perpendicular to the force from the strings.
When you have less material bracing the same direction as the force, you have a weaker top that allows more vibration. The good side is more sound, but the bad side is you can severely weaken the top if you go too far.
If you open up the legs a little more than normal, you will notice that you also open up a larger area at the bottom of the guitar near the bridge. This weakens the area. It also allows it to move more. As a small change to your design, you can make a difference.
Making Changes to Your Guitar
When you make changes to your guitar, you are taking a risk. In the beginning especially, you might not know what some changes really do to your instrument. If you do some research, you can make small changes that make the guitar yours without taking much risk.
My 25 Simple Ways to Customize Your Guitar Without Changing the Tone will show you several great ways to make your guitar custom without taking big risks. It is natural to want to have some fun on the build, and make it yours. This is how you do it safely.
The guitar is such a big build that these are many safe places to show off a little flair. As a woodworker who turned to guitar making, it’s a pleasure to add some personal touches to my instruments. Doing it in a safe way means fun without as much risk.
Guitar Making Tip No. 206 Wrap-Up
The X brace is the standard that all other guitars are judged by. As a guitar maker, you get to create this bracing style your own way. Altering the way you attach the X brace can have a big effect on tone, and you can use that to your advantage.
When you widen the X brace, you loosen the top. When you close the X brace, you stiffen the top. You can make minor adjustments as you build that are tailored to using heavier strings, or weaken the top to compensate for a stiffer soundboard. This is the beauty of being a custom guitar maker.
If you have any questions on Guitar Making Tip No. 206, please leave a comment and I will be glad to answer them. Happy building.
1,001 Acoustic Guitar Making Tips for Beginners
Tip No. 206 is from my book, 1,001 Acoustic Guitar Making Tips for Beginners, which has a thousand more great tips to get your first few builds on the right track. There is no secret to guitar making, just a lot of small things that you need to get right. These tips will help you.
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