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, and from my own observations. I added some 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).

My goal here is to understand the effects of different strutting design geometries on the same soundboard, something that is impossible to do in the real world. I focus particularly on the frequency response of the fundamental mode, as this is a key measure of each model. The models presented here have been "standardized" to allow for comparisons. The standardization involves using 5x5 mm struts that I fit onto the same plantilla to avoid confounding effects of different guitar sizes.

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 as I consider him a great innovator of the classical and the flamenco guitar. 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!

Look also at the Leonardo Guitar Research project for building guitars only with temperate woods.

New! Featured luthiers & Suppliers

I list here a selected number of active luthiers that I believe create instruments of high tone quality and of suppliers that provide high standard products.

I. The Basics

II. Vibration modes of main designs

  1. Antonio de Torres 1888 design

  2. Manuel Ramirez/Santos Hernandez 1912 design

  3. Enrique Garcia 1922, 8 fan design

  4. Santos Hernandez 1923, slanted bar Classical design

  5. Santos Hernandez 1930, Classical design

  6. Santos Hernandez 1934, flamenco design

  7. Hermann Hauser I 1937, ex Segovia design

  8. Marcelo Barbero 1951, Flamenco design

  9. Ignacio Fleta 1960's design
  10. José Luis Romanillos - Bream design

    III. Summary of simulations

Last updated: January 15, 2017