Can you assess this?

[deadedith]

Here is a bracing pattern, off the net (so I know it's true :-)). It's not an uncommon pattern.

I'm a novice, so I look at all sorts of stuff and try to advance my knowledge by assessing it and then bouncing it off the experts.

Anyway, I look at that pattern and the first thing that hits me is: balance. The areas of the top are all supported. The second thing: too much bracing? I don't know, but I would estimate the total mass of that bracing to be roughly equivalent to the 'standard' pattern that has worked well for so long. Third: that's a lot of inletting to cut into the kerfing.

All in all it does not seem like a radical alternative.

So if total mass of the top is in fact roughly equal to standard bracing, and all other things being as equal as possible, how would a pro go about assessing it?

[Jim_H]

I believe that is commonly referred to as a 'double X'. I'm not experienced enough to give you much feedback, but one thing I noticed is that is a big guitar. To me, that bracing pattern looks like it's best suited for really big guitars, perhaps of the twelve string variety?

Just seems like a lot of mass for the strings to move. I wonder how thick the top is?

[deadedith]

My theoretical question is: if the mass is in fact the same or less than a standard pattern, what then do we make of it?

[kencierp]

Gibson tried the double X configuration on j200's and I think other models and it close to put them out the acoustic business --- those guitars are said to be horrible! I'm not sure where to send you to do more research but this is fairly common knowledge. The sound board is a membrane -- like a drum skin it has to be responsive -- which requires a design that allows much flexing without self destruction.

[deadedith]

Really, just looking at it, the only main difference is below the bridge plate, another 'x' instead of the tone bars we normally use. The tone bars have always looked a little funny to me, they do not seem to equally divide up the area below the bridge plate. This second 'x' SEEMS to do a better job.
But if it does not work, it does not work. I don't have the luxury of a lot of wood and time to run experiments, darn it.l
Thanks for the input.

[deadedith]

I snagged this off a web site: I'm not offering this in anything but the spirit of free inquiry :-)

"My current favorite guitar is a C.Fox with double X-bracing: (note - I've attached a pic)
Supposedly, his rationale for this design (which he's used for a long time) is that the diamond around the bridge improves resistance to bridge rotation from string tension, and that allows him to thin out the rest of the bracing.

He also uses a pretty massive neck block and kerfing -- the guitar is basically built like a tank but responds like a Ferrari"

[Jim_H]

Interesting that his comment relates to the rigidity and longevity of the guitar, but doesn't speak to it's effect on the sound.

[deadedith]

Yes, I wish he had, but he did say it was his current favorite, so I assume it was very much to his liking in sound.

[Winston_S]

Here's another interesting bracing pattern developed by the "de Jonge" family.

"The lattice provides a superior structure and unifies the top into one vibrating surface. These lattices generally provide the instruments with powerful projection, clear note distinction, and balance between the strings."................source: http://www.joshiadejonge.com

source: http://www.joshiadejonge.com

[deadedith]

Winston - thanks for the pic. That looks like a LOT of work, worth it if it pays off in clear advantage in sound, of course.
Did you notice the size of that top brace? Gads.
DeJonge makes some really good instruments.