The bajo sexto is a 12 string bass guitar used in Norteno, Conjunto ,and Tejano music from northern Mexico and the south western US. It is usually used to accompany the accordion. I used a 1950's bajo made by Martin Macias as my reference. Martin Macias set the standard for what a bajo is supposed to be and is regarded as one of the best bajo makers. I used spruce for the top, walnut for the back and sides. The neck is magnolia, or poplar, and walnut. the rope binding is made of walnut and poplar. The fingerboard and bridge are both walnut. All of these woods were used on the original Macias, with the exception of the top, on which he used pine. To find out more about this project, check out my blog article on building a bajo sexto: fraulini.blogspot.com/2012/04/building-bajo-sexto.html
It's not my bajo, but to give you an idea, here is the King of the bajo, Rabbit Sanchez, showing how it's done on a 1954 Macias.