Overholtzer flat build
 

I am a (very) amateur player and builder and some time ago I built my first guitar using the information from Art Overholtzer's book. It has cheap maple back and sides and a cheap European spruce top.
I experienced a number of problems (including neck back bow) and the result is definitely not a work of art, however the sound is quite good, having strong fat trebles and a tight balanced bass. It has also remained stable with no signs of a sunken top which apparently can be attributed to a flat top build. However it has not left it's birth place so that may help.
I have also built a Torres style guitar with a domed top and the sound is good but different to the Overholtzer flat build.
I am considering having another go at an Overholtzer style with a view to making (hopefully) a better version as I quite like the sound from my first attempt.
This leads me to the real point of my post and that is to say I believe that the cantilever struts were designed (I presumed it was Overholtzer's original design) to withstand the pull of the strings and prevent a sunken top, although Overholtzer does not mention this in his book. They also may have an effect on the sound producing the strong trebles I have mentioned, a bit like the Bouchet bar.
It may be that Art Overholtzer hit on a effective flat top classical guitar design that overcame the usual problems associated with this way of building, the only downside being the increased neck angle and/or sloping of fretboard. I would be interested to know if anyone here has views on this subject.

It’s been too many years since I last read overholtzer’s book to remember the specifics of his top bracing. If I ever owned a copy of his book, I no longer have it. Aside from aluminum jugs and Brazilian rosewood necks, boiled sides to remove the resins from Brazilian rosewood, about the only thing I remember is the thick tops in the upper bout. I hadn’t remembered flat tops or cantilevered bracing.

I’m currently building two classical guitars with dead flat tops. I don’t expect there to be significant differences in sound between them and my usual domed tops: standard domes are very shallow. I’m using the same bracing pattern as the domed tops.

Hi Charles,
The Overholtzer bracing is similar to the 5 fan Bouchet design except the bridge bar is absent and replaced with angled 'cantilever' struts running from the bridge area at approx. 45 degrees to the waist. This seems to be done (in my opinion) to resist the pull of the strings.
Overholtzer included a drawing of the Bouchet design in his book so I guess he was probably influenced by it.
He also employed an extra long bridge which to some extent partly replaced the effect of the Bouchet bar, although I don't agree with using the bridge to achieve that, due to the extra weight of rosewood.

It's possible you'll get more helpful comments/responses in the custom shop, as this post is specifically about building instruments and that's what the people over there talk about all the time. They're maybe a bit more focused on the steel-string world, but many of the luthiers have built classical and crossover guitars as well, and a bunch of them seem very happy to share their knowledge and experience freely with the forum.