Acoustic Guitar Construction

Last weekend I was in London at the acoustic guitar show.
Not that a big venue, but interesting. I saw Albert Lee and Antoine Dufour playing.

Second I played a very very good guitar. An OM from Dana Bougouis. Nothing special at first sight, but oh man, what a sweet balanced and sensitive guitar. Pricetag about 9000$.
Is it worth that? I don't know, but there will be somebody who definetely wants this one.

http://thenorthamericanguitar.com/bourg ... ck-spruce/

Last, and maybe the most interesting thing for us here: I saw several guitars with just tiny braces on the back.
I played a Taylor 600-something with backbracing not worth mentioning. I guess about 1/3" high, 1/4" wide and ending 1" from the sides.
If this should be stable for years, then I make my backbracing far too heavy.

Herman

I watched the video of the Dana Bougouis guitar and it sounded great.

I would think a thinly braced back would lower its resonance frequency close to or even below the top. A non- active back is braced heavy, and has a much higher resonance than the top. It is is far enough away so there is very little coupling. Trevor Gore recommends setting the back 4 semitones above the top. There is coupling but the resonance peak is far enough away to not subtract from the top and provides an added voice. David Hurd's left brain lutherie book suggests the back being within a half semitone of the top. A lot of coupling.

I suspect the lightly braced back is to get the resonance of the back close to the top.

Ya Ken, that's the one.
It has a torrified top and hardly braced back. As most Taylors, it played well, but with a not suberb setup. Although it had a medium action, it buzzed on the G string, 2nd to 7th fret. It sounded good, but not exceptional. Mayberight for its money. Next to the Bourgouis it did not carry me away.

Herman