www.KitGuitarsForum.com

I'm getting ready to brace the back of my 00-18 build, but I have a couple of questions.

I see a couple of treatments of the lower bout - sometimes the braces are low and flat, sometimes taller/thinner. I assume lower/fatter to improve bass response, taller/thinner for more balance? Not nearly the level of discussion of back bracing as top bracing out there.

I have never really thought of the back braces in terms of response. It has just been easier for me to do 5 of the tall thin ones as I make the laminated braces I use....All the same part, just cut to different lengths.

On my very first dreadnaught I used the flat braces for the lower two postions. On the next 3 subsequent dreadnaughts I used all tall/thin bracing. I could not tell you that there was any difference in sound due to this bracing change, neither was the back necessarily any stiffer in the lower bout with one or the other.....but then different woods were used, etc. I think it might just be a preference thing....looks or whatever.

Kevin

The low and wide back braces in the lower bout are traditional Martin from the "old days" (actually, I have no idea what they did on the 00......but it's what they used on Dreadaught and 000). I've heard arguments that the additional mass of the wide, low braces made it easier to get the back main frequency down near the top frequency. Can't say that if that is true or not as I haven't yet tested that theory so take it with a grain of salt.

Martin just used that set up on braces . At one point there were 5 braces on the back. Not sure when they switched to 4. I do find the lower braces allow more back inferences . The higher more modern bracing was done for a warranty issue as the higher bracing is stiffer and less prone to RH movement .
Martin doesn't bother tap tuning or worry about plate frequency .

Over the years I found that the taller braces indeed seemed less affected by humidity -- I noticed this while the braces where in the free state just in storage. The wide flat 1/4 sawn braces (in some cases) would actually loose their pre-sanded contour -- so now I have settle in on the taller type for all styles.