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Hey guys,

I have used a bridge-o-matic I bought from stew mac to set my bridge on my guitars. I also, gotta be honest here, have been copying the way my store bought guitars(Taylor, Seagull, and Santa Cruz) have their saddles shaped. They are all pretty much the same. Up till now, that's been it on adjusting saddle compensation.

This last guitar, I started reading up on saddle compensation, and found an article on Frank Ford's Frets.com about how he figures compensation. I'm a little confused. He says if the guitar's harmonic is sharp to the 12th fretted note, he multiplies the distance of the first fret by the cents sharp. Then he increases the distance from the nut by that much. What about if your string plays sharp at the 12th fret, but the harmonic is good? Does that mean I make my saddle that much closer to the nut, instead of further from the note?

Also does anyone have any other info I could find on the web about this?

One final question... I was fortunate enough to see a 1930's Martin 000-18 at Guitar Center the other day. Of course, even though I couldn't afford it, I had to take it down and play it and look it over. What an awesome sounding guitar!!! But I did notice that the saddle was simply rounded over with no special ramps. Why did that work back then and not now?

Just trying to learn here.
Sean

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change isn't synonymous with improvement
instagram.com/bucketguitars/

Sean: The harmonic should always be the octave of the open unless there is something wrong with the string. It is the fretted note at the 12th fret that will be flat or sharp.If the fretted note is sharp you have to move the contact point away from the nut. How far up the board did you play the Martin...? Mr. Martin was famous for having bad intonation for guitars made in the 70's but folks still played music on them.Lots of them were good sounding guitars. A good ear can be a blessing or a curse.............so can a bad ear!!!!
Tom

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A person who has never made a mistake has never made anything!!!

Thanks for responding Tom. I feel like a dummy, that should have been obvious to me, thanks. I sometimes try to over think things. I didn't play it that far up the neck, I kinda felt guilty playing it to begin with, $6000.00 is way outta my price range. I was amazed about how light it was and how rich it sounded.

Sean

_________________
change isn't synonymous with improvement
instagram.com/bucketguitars/

Sean: Mr. Martin made some fantastic guitars and Father Time helped to improve things.
Tom

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A person who has never made a mistake has never made anything!!!

One little trick for checking intonation when making a new saddle is to leave the top flat, but get it close to the proper height. Put a small piece of wire (a B string works well) on the flat, string up and move the wire back and forth until the intonation is as good as you can get it (open string, harmonic and 12th fret as close as possible). Mark each side of the wire with a sharp pencil and make that your break point. I've used this on 12 strings to compensate each string of each course - the saddle looks like a rip saw blade but it will play pretty much in tune.

One question about the old Martie - was it's intonation dead on or was it just a wonderful old guitar? Lots of guitars from those days had no slant to the saddles - many didn't play in tune very well.

Edit to add - there was a very scholarly article in American Lutherie a year or so ago about calculating the amount to compensate. It won't be on the web, but if you are a member of GAL you can buy back issues.

One more edit - it is the article by Mark French here - warning, heavie math

http://www.luth.org/backissues/al97-100/al100.htm

_________________
change isn't synonymous with improvement
instagram.com/bucketguitars/

The process I use is a simple one. I tune the guitar open with a Peterson tuner, then compare the 12th fret harmonic with the fretted 12th fret. I adjust the Perterson up or down until the fretted 12th fret matches the harmonic. I put these cents (+ or -) into a spreadsheet I built on excel. It tells me how much in inches I need to compensate the saddle to bring it into tune.

The spreadsheet looks like this:


The numbers in the sharp/flat columns are the cents fron the peterson. In the correction column is the fomular :
=(E8/2)*POWER($D$5,C8-D8)-E8/2 where E8 is scale lenght, D5 is 1.00057779, C8 is cents sharp, D8 is cents flat.

If you don't use excel I suppose you would need a scientific calculator.

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Joe Beaver
Maker of Sawdust

I've used the b-string-offcut-on-the-flat-saddle trick for years, and it works well.

On 12-strings, I file the top of the saddle so that it has two ridges, with a V-notch in between, and then notch out the one under the string that I don't need with a small round file. This looks OK: not too busy.

For the latest 12 that I had at Montreal I made up a test rig (after the one in Gore/Gilet) to get both the saddle and nut compensation. It's a beam, with 11th and 12th frets set in it, an adjustable first fret, and movable nut and saddle. I start with the first fret at the correct distance from the 12th, and the nut and saddle at their 'theoretical' positions. Mot the string at the correct height at both ends. Then fret at the 12th fret, and adjust the saddle until you get an exact octave between the open and fretted strings. Adjust the nut location until you get an exact semitone when it's fretted at the first fret. Go back and re-do the saddle, which will have changed. Re-do the nut. Re-do the saddle. Re-do the nut. The heck with it: the changes are getting too small to worry about - note the locations and go on to the next string.

I had some troubles getting the 12-string numbers; there was a resonance in the rig or the tuner at about G, and since the buyer wanted the 12 set up for open G tuning there were plenty of those. Whenever I got close the needle on my tuner would start to jump around. I ended up doing each string three times, and using a sort of weighted average of the results on the nut. Then I used the string trick to set up the saddle. The result was closer than I've ever gotten with a 12: no string seems to be off by more than 5 cents at any fret, and many are spot on as far as my tuner is concerned. Thanks Trevor! I also used the rig to set up a long scale semi-bari (D-d) the same way: with the nut according to the rig specs, the saddle ended up spot on what the rig said, and the intonation is just about perfect. Ken Bonfield, who owns the bari, already wants me to modify his other guitars for that system.

Used the method Alan mentioned for years when a client wanted better intonation on their instrument. Even did banjos and mandolins once I perfected my technique.

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"Act your age, not your shoe size" - Prince

Great post , Alan (really).

Only problem is, I am not quite sure how to mot the string at one end, let alone both ends ...

Moting the strings is a complicated and secretive venture to say the least. Although I’ve tried time and time again, I can’t quite reached that plateau. It is something to strive for.

One does gain great recognition and a sense of accomplishment once he becomes one of the Moting crew.

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Joe Beaver
Maker of Sawdust

I use a regular calculator, or pencil, or in my head some days...multilply cents sharp (or flat) by .007 and shape the saddly accordingly. I fine tune with my 220 grit sanding, then 600 grit, then buff.

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http://www.presnallguitars.com

murrmac wrote:
"Only problem is, I am not quite sure how to mot the string at one end, let alone both ends ..."

Motting is, as has been said, something of a specialized art, like French polish, only less well known. For those of you who have not mastered it, you can simply _mount_ the string at the correct height, and make snide remarks about 'typos'.

Well there you have it! Finally a motter that is willing to speak the truth, but then Alan is just that kind of guy.

Its common that once a Motter has been discovered he is quick to cover his tracks. This is typical. Usually it will be something like ‘oh, my keyboard must be sticking’, or ‘my secretary made a mistake’. How bad is that? Blame it on your poor secretary? It’s true, Motter’s have been known to stoop that low, just to protect their dark secret.

What chance does a slightly below average builder like me have? The cold hard truth is that some of us will never be motters and will never be asked to join that infernal motly crew.

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Joe Beaver
Maker of Sawdust

I've just been apprised that 'mot' and 'motting' have been used as sexual slang in some parts of the English speaking world. Obviously, since I'd never heard of that usage until today, my enhanced-thumb typing was simply an innocent slip. This also makes Joe Beaver's response to my humor about typos a glaring double entendre, albeit equally innocent, I'm sure. I do have to wonder if there is _any_ word in the English language that has _not_ been used to allude to sexuality in one way or another, at some time or place. I imagine the list of totally 'safe' words would be rather a short one. Gimme a break...

Break extended! Outstanding response, Alan!

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Alan,

How could anyone mistake what you wrote as a reference to.... well, you know what.

After all, you had intended to type mount didn't you? Now tell me, how could anyone in their right mind get that confused with a reference to a certain act..... hey, wait a minute......

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Joe Beaver
Maker of Sawdust

Joe Beaver wrote:
"Now tell me, how could anyone in their right mind get that confused with a reference to a certain act..... hey, wait a minute......"

See what I mean? This just gets deeper and.... oh.... sorry......

I always thought one would Mot the Hoople! Which makes a lot more sense now that the reference is made more clear! It's mount the Hoople! Now..what's a hoople?

....Does it have anything to do with saddle compensation?

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Billy Dean Thomas
Covina, CA

"Multi famam, conscientiam, pauci verentur."
(Many fear their reputation, few their conscience)