Trade Secrets!

Banjo Killer? The scoop on forward X bracing for greater guitar volume.


Issue 51 December 27, 2007

Photo: shaving
ow I make a Banjo Killer with forward X bracing
Banjos are loud! I build them, and I love to play them, but in a bluegrass band their volume is tough for a guitar to compete with. That's why I build my Sams Guitars to be Banjo Killers: using forward X bracing to make them louder. Here’s the story:

In mid-1938 Martin relocated their X braces, moving them back away from the soundhole by about half an inch. This reduced problems with warping behind the bridge, because it stiffened the top — but it lowered the volume of the guitars.

Many builders today, myself included, prefer the original “forward” X bracing. I recommend it for players who will be playing in a group. Here’s how to lay out forward X bracing on our Dreadnought Guitar Kit.

Illustration: forward X bracing
The “popsicle stick” brace wasn’t used in the early 1930s, and isn’t used here.
Illustration: luthier cartoon

The gray areas at left show typical modern bracing, and the white shows the forward X bracing. The center of the X joint moves closer to the soundhole, but you can see that it’s not as simple as just sliding everything forward 1/2".
Bridge plate stock
Illustration: forward X bracing

Illustration: forward X bracing

The X braces are at a slightly different angle, changing from 98° to 100°.

The gap between the soundhole to the front edge of the X joint, (not the centerpoint of the joint) becomes 1".

Shaped braces


Sitka spruce soundboards


Photo: shaving
ow to do it:
1. Make a mark on the centerline 1" below the soundhole.
2. From this mark, draw lines at a 50° angle into the lower body bout areas. With a straightedge, extend these lines onto the upper body. (The two lines at 50° angles to the left and right of center create the 100° X angle.
3. Add a parallel line 5/16" below each line. Your X braces are glued in the 5/16" space between these parallel lines.
4. The four small “finger” braces will keep their relationship to the X braces, just moving forward along with them by 1/2".
Photo: guitar kits We manufacture our Guitar Kits right here in our own shop, so the parts are top quality and everything fits.

Dan Erlewine and I made a how-to-build DVD that comes with the kit.

Photo: guitar kit

Illustration: forward X bracing
5. The two long tone bars still tuck into the X brace at the same location as before, but now they run toward the bass side at a 120° angle.

The shoulder brace above the soundhole stays in the same location.

Behlen ground hide glue
The bridge plate stays in the same place, but it becomes a little longer to meet the wider X brace angle. The flat “popsicle” brace is not used on the forward X braced guitars.
Photo: gluing with a go-bar deck
Here, the X braces and bridge plate are glued up and braced on my go-bar deck. For this photo, I marked the typical brace positions in black, and my forward positioning in red.

Todd Sams signature

Go-bar clamping system