Official Luthiers Forum!

If any of you have ever built a 12 string you have probably compensated the scale length based on the standard 6 string scale + compensation. The odds are that when setting intonation that the upper octave strings on EAD and somewhat G tend to be a bit flat compared to their lower octave counterparts due to the significant difference in string diameters and the fact they are not wound.

So the question is do any of you intonate the high octave strings by filing a different saddle break point for the upper octave string as compared to its low octave counterpart? I tried this once and it is tough because the narrow spacing between the two.

Michael,

Craig Lawrence posted this over on the ANZLF - I'm sure he'll comment further here.

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Dave White
De Faoite Stringed Instruments
". . . the one thing a machine just can't do is give you character and personalities and sometimes that comes with flaws, but it always comes with humanity" Monty Don talking about hand weaving, "Mastercrafts", Weaving, BBC March 2010

Yep I had read that one before. Craig Lawrence took the same approach I do. The reasoning for my questioning here is I received a new takiemacie 12 string jumbo for Christmas. I am not sure why but I did Any way I am going to replace the nut and saddles (split saddle and bbee) with bone and was curious to the members opinion on this subject. I am considering increasing the saddle thickness by .079" to allow me to intonate the high octave stings better.

What .. you didnt like the natural chorusing effect of the flatted strings !!!

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

Tony I have played 12 strign for years (I guess I should say decades to be even close to acurate) and just accepted the micr-slightly off pitch chorusing sound as the norm. but when I build my first verry short scale (23.9" 12 fret on an OM body) the amout of dicrepancy stuck out like a sour thumb. and I knew I had to do something

Besides you are going to get the chorusing affect anyway due t the differences in decay rate and sympathetic oscillation

The easiest way I've found to get them right is this:
1) Use a saddle that is about 3/16" wide, and make it initially with a flat top,
2) when you get the strings on, use a short length of string on top of the saddle to find the correct break point for each one,
3) you will probably find that the break points fall more or less on two lines; a rear one for all of the 'normal' strings and a forward one for the octaves,
4) use a three-square file to remove the material between the two break point lines, making a trough along the saddle, and round off the front and back edges of the saddle,
5) use a needle file to notch out whichever ridge you don't need under specific strings. That is, for the G course, notch out the rear ridge for the octave string, and the front ridge for the normal one.
This should give you decent intonation all the way up. I'll note that you will need to start with the saddle forward of the 'normal' position for a six-stringt saddle, since the octave G requires almost no compensation due to the fact that it's so close to it's breaking point.

G'day Michael,

The link Dave has provided concerning my 12 string intonation is fairly comprehensive so there's not a lot I can add.
I would check that your new guitar is currently intonating well ( on the lower/thicker strings ) in the first place . If it's acceptable , it's simply a matter of routing the slot 2 mm. ( .079 " ) forward of the original slot , and fitting the wider saddle, or in your case, saddleS.
I found a 5mm ( 3/16 + " )saddle works out ideal.
I made a saddle as Alan describes in the first place , but found my final model to be more successful. It allows more of a saddle ramp for the thinner strings, and overall , a less fiddly operation.
The difference between a twelve string that has individually intonated strings and those that don't , is enormous ! They are a joy to play and I get a lot of comments in that regard.

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CRAIG LAWRENCE of AUSTRALIA
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I based my saddle on info I got from Alan a long time ago. Here's a pic of the results using a 3/16" saddle blank. I exposed this pic for the white saddle and apologize for the remainder if the bridge being underexposed. The sound coming from this guitar with all strings properly intonated is significantly different from off the shelf models.

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JJ
Napa, CA
http://www.DonohueGuitars.com

A couple of points I forgot to mention :

You'll find the High "G" needs to have it's leaving point at the extreme front of the saddle to intonate correctly. Also be sure to make these leaving points ( ridges ) definate and precise.

Incidently , ( and slightly off topic ), in case there are any here who are interested in the shared bridge pin method I have used on my bridge , I prepared a tutorial along with string spacing etc .

http://www.anzlf.com/viewtopic.php?t=354

Several advantages here including less weight and footprint along with a clear string pathway ( strings not being nudged sideways by all those neighbouring pins)

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CRAIG LAWRENCE of AUSTRALIA
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