Double X Bracings

[Fernando Esteves]

Hello!
I didn't find a topic about the Double X and started this one.
I didn't find any video on youtube comparing a traditional X and a double X guitars, the only one I found was a top still rough with some tap tuning on them (on these particular, I found the pitch of the double X lower).

How can one compare to the other? Does anyone has a clip of it?
Cheers

[Alan Carruth]

I've been using double-X bracing for years. Here's a shot of the initial trim of the top and back for a 12-fret 000 in BRW and Red spruce. This was intended as a 'fingerstyle' guitar; hence the 'tapered' bracing profile. I've also made them with a 'scalloped' braces for flat picking. I find the double-X to be a lot easier to 'tune', either by 'tap tones' or using Chladni patterns.

When I thought about using this setup I made an 'almost matched' pair of guitars: one with 'regular' asymmetric bracing a la Martin, and one with the double-X. I took them to a luthier's convention, and had 60 people, mostly good luthiers, try them out. Forty of those preferred the sound of the double-X, by a little bit. It was more 'modern' sounding than the 'traditional' top.

I can get you some more information, but not right this minute....

[Karl Wicklund]

Alan, I think I’ve seen you (and certainly others) refer to ‘modern’ vs traditional sound. My ears aren’t all that discerning, but could modern be maybe described as more crisp and centered?

[Alan Carruth]

I'm not sure what 'modern' means either, but your guess is as good as any.

[Karl Wicklund]

Got it!

[Fernando Esteves]

Hey Alan, thanks for the answer!
Do you still have this pair of guitars?

[Alan Carruth]

No; those guitars are long gone.

Here's a shot of the scalloped bracing on an Oak/Sitka Dread.

The top bracing could have been a bit lighter.

[Carl Dickinson]

I use a pinless bridge. Do I need a bridgeplate? I'm bracing a top for a L00 and will try a double X based on Alan's pics.

[Alan Carruth]

I don't think you'd need a bridge plate with a pinless bridge. I don't use them on Classicals.

[Carl Dickinson]

Thanks, Alan.

[Mike Mahar]

I've used the double X brace ever since Al showed me the two guitars he mentioned above. It makes tuning the top with Chladni patterns much easier and sounds great.
Gibson tried double X awhile back it those guitars sounded horrible. I've since seen an old Gibson top with the double X and it is easy to see why. Gibson's braces on that guitar were huge and very thick. They looked like they glued some old Lincoln Logs to the some and called it done.
I've also seen some traditional Martin style braces that were tuned by Dana Bourgeois and he achieved balance by thinning one of the X braces substantially more than to other to compensate for the asymmetry of the bracing pattern. Double X simplifies things a lot.

[Alan Carruth]

Matt Umanov gave a talk at a GAL convention years ago where he mentioned the Gibson issue. He said that, when they were taking down the machinery they had used to make them somebody thought to check the top sander. It was set at .095", not the .125" called out on the prints. Maybe the heavy bracing was a response to that mix-up.