Friday, January 18, 2008

Intonation and saddle position on cigar box guitars

Intonation is the ability of the guitar to sound and play "in tune" at the correct fret positions and if it's wrong, a guitar won't play good at all. Not quite so critical on a fretless instrument as you play mainly "by ear" but you still want to get it right. Here's my method for setting the bridge/saddle position on my CBGs.

The neck will have already been marked out with the correct fret positions from a template which also includes the approximate position of the saddle. As you probably know, the 12th fret lies halfway between the nut and the saddle and gives you the first octave of the same note found on the open string. So that is the important position to get right.

I set the neck in the box to place the saddle about 1/3 from the tail. Don't know if that's the absolute best place for it but it seems right to me for aesthetic and playing purposes. When the neck is fixed and the lid fastened down, I string it up and place the saddle roughly where it should be. I keep the string tension low at this point so I can move the saddle easy. I use the shaft of a small screwdriver as a "slide" (easier to see the exact position over the frets due to it's narrow diameter). Next pluck a string open and either tune it to a set note with an electronic tuner or just listen to it if your pitch ear is good. Put the screwdriver slide over the 12th fret and pluck again. Is it the same note an octave higher exactly? If it is you were lucky and job done.

Assuming it's not spot on, keep plucking and move the slide up or down the string till you find the exact spot. Is it nearer or further from the saddle than the 12th fret position? If it's nearer the saddle (above the 12th) then move the saddle nearer to the nut thus shortening the nut-saddle distance until it's bang over the 12th. If the octave is below the 12th position then move the saddle nearer the tail of the guitar. Once you've got it in the right place you can either mark it's position, slacken the strings and glue it in place or just leave it unglued and tension up the strings to the pitch you want them. My preference now is not to glue because that gives me the option of fine tuning it in the future without ripping it off the box.

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