Thoughts About the Design of the Spanish Guitar


Contents by Juan F. Fernandez-M. (about me)


Please write me if you have any comments to improve these pages.

These pages explore the rich features of the Spanish guitar design by analyzing the essential principles implemented on the soundboards of famous guitar builders using finite Element analysis (FEA).

I base my discussion mostly on the plans available from the Guild of American Luthiers, Roy Courtnall and Allied Lutherie, but I also use designs deduced from published photographs in guitar books and magazines, and from my own observations.

I am currently adding many new designs based on the sketches found in the book "A collection of Fine Spanish guitars: from Torres to the present" 2nd, edition, by Sheldon Urlik (Sunny Knoll Publishing), that is worth every penny.

The models presented here have been "standardized" to allow for comparisons, so I am not claiming that I am reproducing exactly the available plans. In addition, for most of the models, only sketches are available, so I had to make several assumptions that are explained in each case.

My goal here is not to simulate specifically the soundboard of a particular guitar, but to rather understand the effects of different strutting design geometries on the same soundboard, something that is impossible to do in the real world.

The list of guitars is not exhaustive.  I believe I have included the essential instruments from the recent history of the guitar, from Torres to Fleta, with various entries for Santos Hernandez' guitars, as I believe that he was a great innovator for the instrument. A preliminary catalog of Hernandez' guitars found on the web (from reliable sources as fake copies linger out there) can be found here Also, I am posting some  photos of my current project of building a Santos Hernandez-style guitar here.

A note on tropical hardwoods can be found here. Please build responsibly!


I. The Basics


II. Vibration modes of main designs


  1. Antonio de Torres 1888 design

  2. Antonio de Torres "La Leona" design

  3. Manuel Ramirez/Santos Hernandez 1912 design

  4. Enrique Garcia 1922, 8 fan design

  5. Santos Hernandez 1923, slanted harmonic bar design

  6. Santos Hernandez 1924, (almost) parallel bracing long strut design

  7. Santos Hernandez 1930, (almost) parallel bracing short strut design

  8. Santos Hernandez 1930, slanted harmonic bar parallel bracing design

  9. Santos Hernandez 1933, simple 7 fan symmetrical design (flamenco)

  10. Santos Hernandez 1934, short 7 fan symmetrical design with closing bars (flamenco)

  11. Santos Hernandez 1936, slanted harmonic bar variable angle bracing design

  12. Hermann Hauser I 1937, ex Segovia design

  13. Marcelo Barbero 1951, Flamenco design

  14. Ignacio Fleta 1960's design


    III. Summary of simulations



Useful Links


Last updated: February 2016