Beginner's question about tuning.

[djdral]

Hi,

I have a beginner's question concerning mandolin tuning.

It seems that when I tune my mandolin (using this tuner http://www.get-tuned.com/mandolin_tuner.php) there is always a slight problem.

It's kind of hard to explain, but the basic point is that in no two pairs of strings (and I don't mean the courses, I mean a pair of courses, four total strings) does the higher one match the 7th fret of the lower one AND the lower one match the 5th fret of the higher one.

Am I misunderstanding how this works, or is there some problem with my intonation?

Thanks

[Tom C]

...Am I misunderstanding how this works, or is there some problem with my intonation?
Sounds likely

.....no two pairs of strings does the higher one match the 7th fret of the lower one.
if the 7th fret of lower is sharp, your bridge is too close to the nut. Move it towards tailpiece.

...AND the lower one match the 5th fret of the higher one
it will be same note just an octave difference.

[djdral]

Thanks Tom.

The problem is mostly on my D strings... and they are also way sharp at the 12th fret.

I'm not really comfortable adjusting the bridge... isn't it glued down?

[AZStu]

The bridge shouldn't be glued down, but held in place by string tension. Here's a page that discusses how to get proper intonation. It's relatively easy to do. I usually do it when I change strings. I change out the E and G pairs first. Then bring them up to tension. Remove the 4 middle strings (A and D) and then you can move the bridge more easily to adjust the intonation. You could accomplish the same thing without changing the strings by simply loosening the tension on the middle (A and D) strings.

http://www.fretnotguitarrepair.com/MandolinBridges.htm

Here's a more lengthy demonstration of how to change a bridge. Intonation info is near the end.

http://www.folkofthewood.com/8ppmandobridge/sld001.htm

[Michael Gowell]

No, the bridge is moveable...its kept in place by the tension of the strings. Your bridge might have moved when your strings were changed - that's why it is recommended that no more than 2 strings at a time be taken off for replacement.

With the bridge in its correct position the 12th fret will be exactly halfway between the nut and the bridge. Strike a note on any string fretted at the 12th fret. Then strike the harmonic - the same string lightly touched - not fretted - above the 12th fret so it chimes. If the fretted note and the harmonic don't agree the bridge is out of place.

Take the tension off the strings sufficiently so that you can slide the bridge slightly towards or away from the bridge. Tune up one course and see if you've improved the intonation. When you get it right, tune all strings up to pitch. It may work best to concentrate on the "outside" courses, the G and E strings. Remember to slack those strings every time you want to slide the bridge.

EDIT: Stu beat me to it.

[djdral]

I appreciate it, guys.

I actually took it to guitar center (I just bought it a week ago so all their repairs for the next 20 days are free... otherwise I would have gone to a luthier).

I found that their repair guy knew less about Mandolins than I did (which isn't much), but he made the adjustments that you suggested and the intonation is right now.


Thanks for your help!

[extramusical.com]

Please be aware if you put new strings on, you want them to be as close to the same guage as the originals, or else you'll run into the same problem again.