Classical Guitar Back... in 10 Pieces

CE Sobel · #1 05-29-2019, 11:58 PM

Hi AGF,

Here's a quick shot of a recently completed classical, which started it's life as a 1960 DiGiorgio. Three years ago I replaced the destroyed top for my client... a lot of work went into the guitar and the restoration spanned almost 6 months at that time.

This last year we replaced the back. In order to get a good match with the old Brazilian rosewood I did a many piece back cut from 70 year old turning blanks.

As the title states the back is in 10 pieces. Thankfully they are joined together

We were both really happy with how it turned out and so glad that we went forward with the back replacement... the guitar was significantly louder afterwards. My client played it recently in duo with Adam Levin and it was nice to hear in concert

. I'll see if I can post up some sound clips.

redir · #2 05-30-2019, 08:13 AM

Looks great. How many cross struts did you use for the back? Any ideas as to why it's louder? I have always used 3 bars on backs but have been thinking of going with 4 to make the back more reflective and possibly louder.

LadysSolo · #3 05-30-2019, 10:02 AM

It's different but I like the look - nice work!

Gitfiddlemann · #4 05-30-2019, 10:51 AM

Very nice work. What I find most striking appearance wise is how well the individual pieces match up pattern wise.
What does the top look like?

CE Sobel · #5 05-30-2019, 11:10 AM

Quote:

Originally Posted by AndreF

Very nice work. What I find most striking appearance wise is how well the individual pieces match up pattern wise.
What does the top look like?

Hi Andre,

Thanks a lot! Here’s a pic of the new top from a few years back... I salvaged the original rosette and used a top that already had about 30 years of age on it:

CE Sobel · #6 05-30-2019, 11:35 AM

Quote:

Originally Posted by redir

Looks great. How many cross struts did you use for the back? Any ideas as to why it's louder? I have always used 3 bars on backs but have been thinking of going with 4 to make the back more reflective and possibly louder.

Hi redir,

I think it mostly has to do with the fact that the old back was a two ply laminate of Brazilian rosewood and was only about 1.5 mm thick. It was also oddly deformed so overall it was not an ideal component for the guitar and I think damped the sound.

As far as 3 vs 4 braces, I think it needs to be considered also how stiff the braces are as that ultimately impacts the back performance the most. Also the body size. One thing that gets overlooked on classicals in the stiffness of the upper bout of the back. In the 70’s the great French luthier Daniel Friederich did many experiments at the acoustics laboratory at the university of Paris (not sure the exact university). Among these they found that one sure way to kill the sound of a guitar was to build the upper bout of the back too stiff. Whatever bracing sceme the back utilizes I think care has to made to build that area “just right”.

Thanks for your interest!

Skip Ellis · #7 05-30-2019, 12:13 PM

Hey Chris - good to hear you're still at it. Another fine piece of work.

Gitfiddlemann · #8 05-31-2019, 09:22 AM

Quote:

Originally Posted by CE Sobel

Hi Andre,

Thanks a lot! Here’s a pic of the new top from a few years back... I salvaged the original rosette and used a top that already had about 30 years of age on it:

Really nice work. And so, a quality instrument on the brink of death was brought to life by a gifted craftsman. It's a feel good story too!

Would love to hear sound samples as well!

CE Sobel · #9 06-01-2019, 01:07 AM

Quote:

Originally Posted by AndreF

Really nice work. And so, a quality instrument on the brink of death was brought to life by a gifted craftsman. It's a feel good story too!

Would love to hear sound samples as well!

I'll contact my client and see if he has some! Thanks a lot!