getting perfect intonation:

[300win]

Just finished up about an hour ago of working on my mandolin bridge. Thought I would post this info here as it might help someone else with the same problem. This took me about 1 1/2 hours. The mandolin I was working on is a F-5 Gibson Jam-Master that I bought last year. It's a good mando, but the intonation has always been out on the A and D courses, not much, but enough to nag me somewhat. Anyway here is how I did it. Tools I used were my small pocket knife with a very sharp thin small blade, a piece of wood about 4x1x1/4, a small piece of 200 grit sandpaper, used my old Korg ca 20 tuner with alligator clip attached to the treble side of the saddle. First I checked that the bridge treble side and bass side were in perfect intonation at the 12 th fret, then begin checking first my A course then my D. Both were flat, so I run down the A's and using the knife trimmed a little off the back of the saddle, then sanded it, I did this in small increments until the A course was also in perfect intonation, then I did the same to the D. Also lowered the action a smidge. Now my mandolin is like it should be, no flats, no sharps in intonation. This was not hard to do, all you have to do it take your time and do a little at a time. Trim a little, then run the strings back up to pitch, see where you are on the tuner while checking the intonation, then adjust as needed. Most probably know this, but for the ones that didn't if they were/are running sharp you would trim a little off the front of the saddle. Just thought I would submit this to help out anyone that might need the info. And no I did not put one scratch or ding in my mandolin.

[billhay4]

I can't get my head around the idea that trimming off the back of the saddle would change the intonation at all. Isn't the pitch determined by where the string breaks over the bridge? If so, how does trimming the back change this point? I would think you'd have to add a bit to the front of the notch to achieve a flattening of pitch.
I'm not doubting your work, just asking a question.
Bill

[300win]

I can't get my head around the idea that trimming off the back of the saddle would change the intonation at all. Isn't the pitch determined by where the string breaks over the bridge? If so, how does trimming the back change this point? I would think you'd have to add a bit to the front of the notch to achieve a flattening of pitch.
I'm not doubting your work, just asking a question.
Bill

Well give this some thought. If you lessen the thickness of the saddle where the strings go across it either way, front or back, you are changing the strings break angle. Think of it this way; say the saddle is 1 inch thick { an example only} and you have the string going across it, now say you take a 1/4, or 1/2 inch off the thickness, is not the string angle going to be changed in relationship to the tailpiece ? Does this make sense ? I'm not too good about explaining scientific stuff, but I am a retired carpenter and cabinet builder so I do understand angles. And all I can tell you is that what I did worked, and the results were perfect, not close, but perfect intonation. Maybe some of the luthiers will read this and put thier 2 cents worth in, and can explain it better than I can.

[Hans]

What's "perfect"?

[Big Joe]

You may have corrected the notes open/12th fret, but tempered tuning will not allow a perfectly intonated instrument across the fingerboard with a conventional nut and mandolin saddle. Not trying to start a controversy, but intonation on most stringed instruments is a relative thing more than an absolute. Often setup is done to make it the best across the area where the instrument is actually played more than open/12. The design of the mandolin does not lend itself to extremely accurate intonation so it is a matter of determining where you want it most in tone and then how to achieve that particular goal.

Most mandolins when checked open/12 if they are accurate on the E and G will be off a bit on the A and D. However, they play pretty well in the first seven or so frets and not noticeably off to the human ear unless you play quite a ways up. Bridge use and positioning will also affect the intonation as does neck angle and bridge height and truss rod adjustment. Merely making adjustments to the saddle on those strings will be fine... as long as nothing moves or you don't change string guages or brands or the humidity does not cause the top to rise or fall or you don't adjust the saddle up or down...or...or...or???

I congratulate you on your efforts and the success you have. It is good to see one experiment and find a solution to the problem they were experiencing. I merely wanted to point out that there are many things involved in a setup that most don't consider. Not trying to lessen the value of your work or experiment.

[300win]

What's "perfect"?

Well according to my tuner I'm dead on open 12th, harmonic 12th, and closed 12th. Also dead on at the 7th with noted A matching the open E, noted D matching the open A, and noted G matching the open D. I know that tuner is way better than my ear, so I guess it's as close to perfect as it can get. Also notes true from the nut as far as I can note on the board in all chord positions. I'm definatley more pleased now. Just that the way it was before I could even detect a subtle differance in the 7th fret position which I did not like.

[300win]

You may have corrected the notes open/12th fret, but tempered tuning will not allow a perfectly intonated instrument across the fingerboard with a conventional nut and mandolin saddle. Not trying to start a controversy, but intonation on most stringed instruments is a relative thing more than an absolute. Often setup is done to make it the best across the area where the instrument is actually played more than open/12. The design of the mandolin does not lend itself to extremely accurate intonation so it is a matter of determining where you want it most in tone and then how to achieve that particular goal.

Most mandolins when checked open/12 if they are accurate on the E and G will be off a bit on the A and D. However, they play pretty well in the first seven or so frets and not noticeably off to the human ear unless you play quite a ways up. Bridge use and positioning will also affect the intonation as does neck angle and bridge height and truss rod adjustment. Merely making adjustments to the saddle on those strings will be fine... as long as nothing moves or you don't change string guages or brands or the humidity does not cause the top to rise or fall or you don't adjust the saddle up or down...or...or...or???

I congratulate you on your efforts and the success you have. It is good to see one experiment and find a solution to the problem they were experiencing. I merely wanted to point out that there are many things involved in a setup that most don't consider. Not trying to lessen the value of your work or experiment.

Note taken Big Joe. I understand what you're saying. I'm happy with it, and it's good all over from nut to as far as I play one. Also lowering the G side action a smidge helped out the playing ability of it. I got old arthur in the fingers so I know this is going to pay off in the long run. Neck looks good to me. I've fooled around with string instruments a good while, did not just fall off the turnip truck, but by no means am I a luthier, not even close, but over the years out of nessecity due to light funds, I've had to read and learn myself how to do some things. Could never afford a pro. set-up. I've never tried to do anything until I had gleaned as much info as I could, and then only if I was sure I could do it. Now if I could just raise the money to bring you my old D-35 to repair, I'd be all set. I'll be there in Nashville someday with it if it's ever possible. Thanks for the info, and not stomping me for being an amature lol.

[Jim Garber]

Since we are on this subject, any clues how the Buzz Feiten system differs from traditional methods of intonating and is that system at all applicable to the mandolins vs. the guitar?

[Philphool]

Not to question, but can any of you answer billhay4's question?
I sure don't see it. If it worked, great. But I'd like to understand the theory.

[John Flynn]

I know both a luthier and a music store owner who have seriously evaluated the Feiten system. It works by adjusting intonation at the nut and the bridge, as opposed to just the bridge. Both of those independent sources reported the same things:
1) It does work, for any fretted stringed instrument. However...
2) It's more trouble than it's worth, both in time to do it and what the Feiten people charge in training/licensing fees. Both people I know who evaluated it ultimately rejected it.
3) It's only "perfect" for a given set up with a given set of strings, in a given condition, and a given string height. Change any of the variables, and it is no better than doing it the conventional way.

You also have to wonder about an instrument setup system that has the word "Buzz" in the title! :))

[300win]

Not to question, but can any of you answer billhay4's question?
I sure don't see it. If it worked, great. But I'd like to understand the theory.

I'll try again. If your mandolin is noting flat you move the bridge forward, if its noting sharp you move it back, we all know that. Now on what I did since my A and D were noting flat, I took off wood on the back side of the saddle thus in effect shifting the string break forward. Would have been right the opposite if it were sharp, I would have removed wood from the front of the saddle thus in effect moving the break angle backwards. That is as simple as I can explain it. Sorry I can't do any better, I just know for a fact that it DID work. And it is not the first time I've done this. Although other times were on lesser quality mandolins, it worked on those also. Just trying to help out here, not meaning to act like I know any great deal, as I said I'm no luthier. I just thought of something you might could try to see what I'm talking about. Loosen one of your strings, wedge a small piece of paper either on the front under the string or back, and make it where it will either push the string forward, or push it backwards toward the tailpiece and see what happen with your intonation. Not sure if this would work, but it might, and if it does then what I've been trying to explain will be as plain as day to you.

[foldedpath]

Not to question, but can any of you answer billhay4's question?
I sure don't see it. If it worked, great. But I'd like to understand the theory.

It doesn't make sense to me either. The string vibration is stopped at the first place it makes contact with the saddle, and it's the length of vibrating string that determines the pitch of a fretted or open note.

Shaving the back edge of the saddle where the string isn't vibrating could change the break angle, which might affect tone or volume. It shouldn't change the physical length of the vibrating string, which is what intonation is all about (as well as side effects like stretching the string to touch a fret, width of fret, etc.). Unless I'm missing something, I don't see how it would alter intonation at all. Maybe the OP inadvertently changed something else like the bridge position during the adjustment? Or maybe it's an odd saddle design with the actual contact point more towards the rear, and a widened area or "ramp" in front? I dunno.

Another thing: it's not easy to adjust intonation with an inexpensive tuner with a simplified LCD or LED display. The internal resolution in the electronics might be very good, but the display doesn't have the resolution to show it. It's easier to set intonation with a strobe tuner, or one of the "virtual" digital strobe tuners. You don't *have* to use an expensive strobe tuner to get in reasonably good intonation, but it sure helps!

I'll also second Big Joe's comment about the variables that can affect intonation, especially a change in string brand or string gauges. I wasn't able to quit messing around with my bridge position until I was through testing all the string brands and sizes I was interested in, and finally settled on one brand and gauge size. Always check intonation again if you switch string brand or string gauges, and do it with a fresh set of strings.

Intonation is such a compromise with any 12-TET fretted instrument that I'd have a hard time calling it perfect, even when I know I'm as close as I can get it. I have constant clashes over tuning with the fiddle player in our band, because he tunes in perfect 5th's, and I can't do that.
:confused:

[B. T. Walker]

You also have to wonder about an instrument setup system that has the word "Buzz" in the title!

You made me spew my iced tea! :)) I thought it but didn't post.

[300win]

It doesn't make sense to me either. The string vibration is stopped at the first place it makes contact with the saddle, and it's the length of vibrating string that determines the pitch of a fretted or open note.

Shaving the back edge of the saddle where the string isn't vibrating could change the break angle, which might affect tone or volume. It shouldn't change the physical length of the vibrating string, which is what intonation is all about (as well as side effects like stretching the string to touch a fret, width of fret, etc.). Unless I'm missing something, I don't see how it would alter intonation at all. Maybe the OP inadvertently changed something else like the bridge position during the adjustment? Or maybe it's an odd saddle design with the actual contact point more towards the rear, and a widened area or "ramp" in front? I dunno.

Another thing: it's not easy to adjust intonation with an inexpensive tuner with a simplified LCD or LED display. The internal resolution in the electronics might be very good, but the display doesn't have the resolution to show it. It's easier to set intonation with a strobe tuner, or one of the "virtual" digital strobe tuners. You don't *have* to use an expensive strobe tuner to get in reasonably good intonation, but it sure helps!

I'll also second Big Joe's comment about the variables that can affect intonation, especially a change in string brand or string gauges. I wasn't able to quit messing around with my bridge position until I was through testing all the string brands and sizes I was interested in, and finally settled on one brand and gauge size. Always check intonation again if you switch string brand or string gauges, and do it with a fresh set of strings.

Intonation is such a compromise with any 12-TET fretted instrument that I'd have a hard time calling it perfect, even when I know I'm as close as I can get it. I have constant clashes over tuning with the fiddle player in our band, because he tunes in perfect 5th's, and I can't do that.
:confused:

Well I give up. I guess to everybody its wrong, but it worked this time and its worked before. All I can say is my mandolin is dead on the money anywhere on the board I want to note it. As far as my tuner I had it checked once against a strobe tuner and it is true. It is not one you fasten on the headstock, it is a old Korg ca 20 with a alligator clip I fasten to my bridge. And as fas as the bridge goes, it is the factory bridge that Gibson put on it, and looks just like a Cumberland I have on my A-9. Now speaking of my A-9, when I installed the Cumberland bridge on it, I did not have to do anything to it to get the same results that I've done on the one on my F-5. Let me ask this one more thing. Lets say you have your bridge sitting on your mandolin, and you move it forward, didn't you just remove wood from the back in relationship to the distance between it and the tailpiece ?, and if you did the opposite would there be not less wood in relationship of between the bridge and the nut ? Ya'll can call me crazy, thats ok, I was just trying to tell something that works. And no it did nothing detrimental to the tone or volume, or any other way damage my mandolin it just made it better, heaven knows I would do no such thing, it took me 40 years to be able to get a Gibson mandolin. I would not do anything to damage it. Maybe I should not have said perfect, seems that upset some somewhat. But anyway thats the best I can do to explain, as the old feller said when the whiskey jug busted, "we're all dry now ".

[Rob Gerety]

Might help to see a picture before and after.

Seems to me that to change the intonation you have to change the length of the string between nut and the bridge contact points. When you removed wood from the back of the saddle did it have the affect of moving the contact point toward the nut a bit?

[woodwizard]

Seeking perfection... nothing wrong with that. Glad it worked for ya.

[Philphool]

Well I give up. I guess to everybody its wrong, but it worked this time and its worked before. ......".

300win,
I'm not disputing your experience at all. In fact, I'm wondering whether there is something going on that I might not be thinking of when I'm working on intonation problems. Removing wood from the backside doesn't seem a part of the equation in my mind, but I'm not averse to learning a new principle that I haven't considered before. I think I need more data before I form an opinion even though I'm presently confused. Maybe I'll experiment one of these days and see if I can replicate your experience.
Thanks for sharing.

[Nick Triesch]

Years ago I took a nice mandolin to a master guitar maker here in San Diego and he told me that getting perfect intonation on a mandolin was really hard. He said they were strange little beasts. It's true...Set up your mandolin perfect and then note say an A note in the first position. Then find the A notes all up and down the neck. It's really hard to find the notes to be true. They will be sharp or flat. It works much better for a guitar but most mandolins I find are just not true up and down the neck.

[Lefty Luthier]

Just a wild guess but it is possible that when trimming the saddle from the back, the saddle was rocked a bit, which would be the actual reason intonation changed. When I am setting up a new instrument for the first time, assuming all frets are precisely located, I find it best to locate the bridge at the point where the E strings are correctly intonated and then adjust the other strings' notches fore or aft depending on flat or sharp.

[fishtownmike]

And i thought someone finally solved the problem of imperfect intonation. I knew i was getting my hopes up.;)

[Fretbear]

It's another reason to keep an eye on your bridge-saddle and keep it straight up, or slightly tilted back if that's where it was set to be. When your instrument is perfectly set-up, the saddle wants to be right where it was initially set, and you will not only get more sonic pop and volume there, but the intonation will be spot-on in that position and not anywhere else.

[Michael Lewis]

Without actually seeing the instrument I can only guess at what actually happened. Most probably the notches are cut with an angle down toward the neck instead of the correct reverse. Foldedpath mentioned this, and is probably right. It is also possible that the saddle had very shallow notches and the strings were contacting the saddle at the rear edge and due to the stiffness of the string slightly raised above the surface just in front of that. Without a doubt, the string will react to the pint of contact, that is just physics. Magnification can help shed some light on the actual contact.

[300win]

300win,
I'm not disputing your experience at all. In fact, I'm wondering whether there is something going on that I might not be thinking of when I'm working on intonation problems. Removing wood from the backside doesn't seem a part of the equation in my mind, but I'm not averse to learning a new principle that I haven't considered before. I think I need more data before I form an opinion even though I'm presently confused. Maybe I'll experiment one of these days and see if I can replicate your experience.
Thanks for sharing.

Well Philpool I never intended to lead anyone astray on this post, nor to dispute any other members knowledge. Who am I to say anything works that luthiers know about. It might not make sense to none of ya'll which seems the case, but I swear on my mothers grave it does work, and contrary to what some have said, my bridge was not rocked forward, or moved in any way after I got the E side and G side in the right position on the top plate for correct intonation. This is a high quality bridge on a high quality instrument, it is as close to perfect on the top plate as you can get. I can't post pictures and even if I could it wouldn't show anything that you could tell either before or after. I'll not post anything else as it seems that it is pointless to further discuss it. Again all I can say is now my Gibson F-5 has as close to perfect intonation over the entire fretboard as you can possibly get. I see that no one commented about my A-9 being the same way after I installed a Cumberland bridge on it, but not having to do anything to it, and I have the same thing on it, as close to perfect intonation over the enite fretboard. I find it odd that the consensus is that a mandolin cannot be dead on over the entire fretboard for correct intonation in the notes. One of the above posters said you can never get the A right that it would be out up and down the neck depending on where you are noteing it. I find that hard to believe, as I have never experienced that myself if the mandolin was any good, if it had the bridge out on intonation or the neck was warped or improper relief, or bad frets, yea I could see that might happen. Like I say, I'll hush up about it. The whole purpose of me posting this was to try to help anybody out that might be expereincingthe same problem, but it seems that now everyone thinks I'm an idiot. But thats ok, I've been called that and worse before, but I've also in the past made believers otherwise out of folk that have thought that of me. No harm done, no hard feelings towards none.

[Philphool]

No, no, 300win. All we can do is report what we do & see. Don't feel bad. Sometimes what we see happen occurs because of things other than what we are thinking about & that's what I was trying to get my mind around.

I had a luthier graft on a bit of ebony to the front of my saddle at the A strings to get the intonation right and it's darn close to "perfect" intonation all the way up the neck now. So your experience isn't so strange to me in that regard.

Always willing to learn, but I really do like to know WHY things happen the way they do. Just my way of thinking.
Thanks again. Keep pickin' :mandosmiley:

[brianf]

I can't get my head around the idea that trimming off the back of the saddle would change the intonation at all. Isn't the pitch determined by where the string breaks over the bridge? If so, how does trimming the back change this point? I would think you'd have to add a bit to the front of the notch to achieve a flattening of pitch.
I'm not doubting your work, just asking a question.
Bill

If trimming down the back of the bridge slot sharpens the pitch, then it might be concluded that the break point was at the point that was trimmed. Reducing height at that point, will shift the break point to the front, thus sharpening the pitch.

[300win]

No, no, 300win. All we can do is report what we do & see. Don't feel bad. Sometimes what we see happen occurs because of things other than what we are thinking about & that's what I was trying to get my mind around.

I had a luthier graft on a bit of ebony to the front of my saddle at the A strings to get the intonation right and it's darn close to "perfect" intonation all the way up the neck now. So your experience isn't so strange to me in that regard.

Always willing to learn, but I really do like to know WHY things happen the way they do. Just my way of thinking.
Thanks again. Keep pickin' :mandosmiley:

Well I said I was done, but I will reply to you since you are a son of the Old North State. I do appreciate what you said, and also just to you, I got to thinking that maybe it is the 'bearing' point of the string on the bridge, maybe that is what changed the intonation, although you do have a differant break angle. Maybe that is why it works ? We all talk in thousandths of an inch on strings, frets being placed properly, bridges being fitted correct, etc, everything on the instrument a thousandth of an inch makes a big differance, then why not what I did, you can measure that in thousandths of an inch, and just maybe, maybe it is the .1000 of an inch bearing point of the string on the bridge that does make the differance in being close in intonation, or dead on in intonation. I ain't too educated of a guy, only got a GED, which by the way I'm proud of, and I know there are some very intelligent folks on here that honestly when I read thier post sometimes I have no idea what they are talking about. But again I say that what I did, and have done in the past, does work every single time. Man if you ever do try this, pm me the results you get, I would surely like to know that it ain't no fluke, but again how could it be, as this is around the 7th time I;ve did this. Thanks again, and as Gen. Lee said, " God bless the tar-heel boys.

[farmerjones]

i think i get it, from your first explanation, win:

http://www.mandolincafe.com/forum/attachment.php?attachmentid=56337

[Big Joe]

Whatever the reason for the success, I applaud Win300 for his achievement. After all, anyone named after a gun that cool has got to have something going for him :) .

Someone asked about the Buzz Feinten system. We do both the Feinten and the Earvana systems. I have an Earvana in one of my electric guitars and I love it. It does help with some of the issues with intonation. It was not that big a deal for me to install and intonate. It is not as complicated as the Feinten system and does a great job. There is currently nothing designed for the mandolin, however, if we ever get time we would like to work on one that would help correct the issues we find. That is still a bit in the future though. I think a system can be done that will work with the nut and saddle to help correct many of the issues with intonation on the instrument.

I want to put one of the systems on my electric bass. I notice the intonation problems more on it than the other instruments. Of course, it has larger diameter strings and quite a bit longer scale. They do have systems designed for bass, I just have not had time to mess with it yet.

We have installed some of the systems on some of the studio and road pickers guitars and they like the extra help it provides. The Feinten system is a bit more complex to get set up with and to get understood, but can be a bit more exacting. The cost to install that nut is not that much more than a regular nut on a guitar but does take a bit more work. I personally think it is worth the expense. Everyone is entitled to thier opinion, but the players we have used it on have been very happy. Many of our customers are pro pickers and are very fussy about thier instruments and the way they play. I mean extremely fussy and it has to play just the way they want. Not close...exactly how they want. Often they are not all that great at explaining what they want so we have to work with the to determine what they want. They ALL want the best intonation possible. They can hear things very clearly that most people most places would not be able to hear. That is what they do for a living and they spend a lot of time in the studio where it has to be dead on... not just close. Whatever one has to do to get it to play like that is what they want and what we have to provide. In those cases, the Feinten or Earvana system is a good choice. In many cases it is not needed and we can get it dialed in without having to resort to those, but sometimes it takes that little extra to get the job done. I am just glad there are more options available than we had ten or fifteen years ago or thirty or...

[Steve Farling]

When I first read this post I was thinking the same as most of you have already stated. My immediate thought was that it would be better to first set the bridge with the A & D strings intonated and shave the front edges of the bridge for the G & E strings. But with much more thought on the subject, and taking into consideration the comments of some about how futile it is to even attempt this from past experiances, and, farmerjones' very nice illustration, I would like to suggest that 300win just may have stumbled onto a solution to the previously thought to be unatainable "perfect mandolin intonation" problem. Physics does indeed dictate that string length is the deciding factor, but perhaps everyone has previously been measuring from the wrong side of the bridge.:confused:

[300win]

i think i get it, from your first explanation, win:

http://www.mandolincafe.com/forum/attachment.php?attachmentid=56337

You got it !

[300win]

When I first read this post I was thinking the same as most of you have already stated. My immediate thought was that it would be better to first set the bridge with the A & D strings intonated and shave the front edges of the bridge for the G & E strings. But with much more thought on the subject, and taking into consideration the comments of some about how futile it is to even attempt this from past experiances, and, farmerjones' very nice illustration, I would like to suggest that 300win just may have stumbled onto a solution to the previously thought to be unatainable "perfect mandolin intonation" problem. Physics does indeed dictate that string length is the deciding factor, but perhaps everyone has previously been measuring from the wrong side of the bridge.:confused:
Steve, thanks, and I think you along with farmerjones said what I've been trying to say the whole time, just not too good about explaining things.

[mandroid]

Freely Vibrating string length is the other side of the bridge, those illustrations, both, are not good physics.

Teacher would get out the red marker . (I'm Not a teacher , just a Mechanic)

you want inside to inside , rather than one inside on the left, and an outside on the right.

:popcorn:

[Steve Farling]

This is a great discussion. What a coincidence. I'm a mechanic also and understand the mechanics of this situation. What I'm suggesting that since this has been a problem for so long, for so many, there must be something that most, have been missing. Perhaps when dealing with short string lengths, under high tension, the full with of the surfaces supporting the string become involved too. (Nut & Bridge):disbelief:

[300win]

Here it is the final say I'll say about this. It works [period}, sorry some if not most can't understand. I ain't pulling anyones leg on this, I am as certain of this as anything I've ever been in my entire life, IT WORKS.

[farmerjones]

Exactly Steve,
I believe the string vibrates from the breakover point.

While i see you point mandroid, the illustrations are exagerated to make the point of, i think it was, the second post.

i'll be here all day. nothing better to do.

:popcorn:

[brianf]

Freely Vibrating string length is the other side of the bridge, those illustrations, both, are not good physics.

Teacher would get out the red marker . (I'm Not a teacher , just a Mechanic)

you want inside to inside , rather than one inside on the left, and an outside on the right.

:popcorn:

My point, exactly. the breakpoint on the nut is, or should be, towards the bridge. The breakpoint on the bridge is, or should be towards the nut. Re this discussion, the high point of the bridge slot is the breakpoint, and if is towards the tailpiece to start with, filing it down will transfer the breakpoint forward, making the pitch sharper.

[Steve Farling]

300win, I have a 2003 Gibson F5-G that has the stock bridge with the typical intonation inconsistencies. I've decided to try correcting it your way. I really think you have stumbled onto something here, and being the experimenter that I am.......
I figure if it doesn't work, it'll be an excuse to get a new Cumberland Acoustic bridge that I've been wanting anyhow! It might be a week or two before I get it done, but I'll be sure to post the results in this thread. You get all the credit man, if it works!
Anybody else willing to try this theory out????????

[foldedpath]

This is a great discussion. What a coincidence. I'm a mechanic also and understand the mechanics of this situation. What I'm suggesting that since this has been a problem for so long, for so many, there must be something that most, have been missing. Perhaps when dealing with short string lengths, under high tension, the full with of the surfaces supporting the string become involved too. (Nut & Bridge):disbelief:

With respect, nothing is missing and there are no no undiscovered magic bullets. The pitch of a note is determined by the length of string that is free to vibrate, period. The string doesn't vibrate past the first point of contact with the saddle. There may be some induced vibration of the shorter length of string running back to the tailpiece, but that will be a different pitch and overtone series (the reason some people like to use damping back there), and it's not what you deal with when setting intonation anyway. Intonation is adjusted by moving that first point of contact at the saddle, by either physically moving the bridge or adjusting the shape of the saddle.

It's not rocket science. Luthiers and musicians have been dealing with this for many years. If 300Win managed to adjust intonation by shaving the back side of the saddle, then that's where the point of first string contact was located. This would be an unusual case, but hey... if it worked, then fine. I don't think this justifies recommending the technique for general use, because most saddles will have the contact point at the side facing the nut. I think that's the only reason there has been some backlash; it's the idea of recommending it as something everyone should try.

I think it's great that we can share ideas here about things that work, but when talking about a general-purpose technique for something like intonation adjustment, it should apply to the majority of cases (i.e. saddles with front contact of the string), and not the quirky exceptions.

Also, not to harp on this too much... but there really is no such thing as perfect intonation on a fretted string instrument. The mechanics simply don't allow it. You can have theoretically perfect 12TET intonation on an instrument like a piano or concertina (although various "sweetenings" away from 12TET are usually applied), but fretted instruments introduce the complication of strings, which have to stretch at different points along the fretboard to make contact with the frets. This means the open string and 12th fret harmonic notes will always be flat, relative to a fretted note, because the string has to be stretched to hit the fret. And the amount of stretch is different for every note! The art of intonation means making adjustments for this, and it can never be perfect. We aren't hitting individual keys like a piano, we're stretching the strings with our fingers.

The classical guitar luthier Greg Byers has an article about intonation (http://www.byersguitars.com/Research/Research.html) on his site that explains some of this, with a few solutions like compensated nuts that are probably overkill for a short-scale instrument like the mandolin. The goal is to get "close enough." Aiming for perfection on these little beasts will just drive you crazy.
:)

[Jeroen]

Usually I am with Michael Lewis, whatever he says.

Still, a few risky thoughts to help find some theoretical support for 300Win's results:

Wood is wood and will allow some vibrations. I think that means that the classroom physics of point to point waves are just a tad too theoretical for strings between a vibrating wooden support on one side and a slippery fret on the other side.

Another:
I would guess that the part of the string behind the bridge will vibrate opposite because of the string's rigidity. That effect will probably be more pronounced on a thinned bridge, making the effective breakpoint less fuzzy, and, moving it forward.

[foldedpath]

Exactly Steve,
I believe the string vibrates from the breakover point.

How can the string vibrate forward of the breakover point, if it's still under high pressure in the saddle slot forward of that point, the way most saddles are designed?

[farmerjones]

http://www.mandolincafe.com/forum/attachment.php?attachmentid=56347

Howzat?

Oh BTW,
I had a solid body electric kit come in with the bridge location wrong. Stud holes were drilled into the body wrong. I bought an adjustable bridge and flattened the base for the flat top. The guys over in the other section, highly recommended a strobe tuner. I have to agree. That really helped. No such thing as perfect has to do with temperament, but the strobe more easily "sees" halves, and or doubles, when properly locating a bridge.

[Dobe]

Howzat?

That's better !! Physics is physics. Period. . . .:popcorn:

[Big Joe]

Of course we can argue the applied or theoretical physics of intonation until we are blue in the face. With all the math and science we can muster we can tell why something is impossible, however, that does not alter Win's discovery. He has found the intonation that is perfect for him. That is a happy moment in the mandolin world for sure.

Mandolins are one of the more difficult fretted instruments to get in perfect tune everywhere. It really is not possible. We have learned to deal with these inconsistencies because there is not perfect solution. Our ears come to the point where the best we get becomes perfect to us. We ignore those slight pitch errors and just enjoy the music. The human body is an amazing machine that allows us to foregive these discrepancies and enjoy those moments. However, when everything is not in proper harmony as best as can be we do hear it and it irritates us. That point of irritation is different for everyone. I may tolerate more less perfect tuning than you or vice versa.

My wife hates going to music venues with me. I can hear when a string is not in tune. I am not talking about the minor tuning issues with stringed instruments. I can often hear them, but like others have come to accept and ignore those. I am talking about listening to a band or singer and hearing when they are off or out of tune. I will comment that I wish the guy would tune his instrument and my wife just glares at me. She did not know it was not in tune. I like to further irritate her by telling her which string on which instrument is out of tune. The same with vocals. She does not realize there is anything wrong because she is not aware of it all day long all day every day.

I don't have perfect pitch by any means, but I can hear when something is out of tune or perspective with everything else. Some have far better hearing of those things than me. It is when my amatuer or non musician friends are with me that I realize how little they can hear. Nashville is an interesting town and the level of talent so high that you can easily become a bit jaded by hearing music that is not in that upper tier of perfection. When I go to another city or town and go listen to music with friends they love to have me hear the "great" musicians where they are. I don't have the heart to tell them that while they do a very good job, they are usually not ready for Nashville. The things I hear they cannot and they assume the talent pool is greater than it is. I don't mean to sound elitist at all, just an observation. I am not in the same league as many of the Nashville pickers and have never claimed to be. I can get around my instruments, but have no dilusion of granduer :) . It is just an observation of how our ears develop to tones and sounds and groups of sounds and how we also don't hear them. Again, just an observation....oh...and there are great musicians all around the country and not all of them in Nashville. Nashville just has a higher population of great pickers because this is where their work is.

[Rob Gerety]

It may not make any sense, but if it works, it works.

I've learned to keep my mouth shut so my wife doesn't roll her eyes. Took 35 years to figure it out.

[Jeroen]

If the wood of the bridge allows some vibrations and if the string rigidity will cause some movement within the bridge slot, I would expect an effect like I tried to visualise in the image.

[Larry Simonson]

In science, if the facts don't fit the theory, then the theory is dismissed. Theory opines, experiments decide! It seems OP has done the experiment more than once with consistent results and the observed behavior doesn't fit the theory. I'd say lets see if others can repeat this work and if so, the world stands to benefit.

I'm of the belief that the bridge is a very subtle device where minor changes can have significant consequences. I also believe that the note a given string, at a given tension, produces is a function of more than its length. So what OP is saying seems tenable to me.

[Mandoist]

He has found the intonation that is perfect for him.


I would imagine that is all one can hope for? Fun reading all the science, "solutions" and hypothesis...but isn't the bottom line the fact that there is no such thing as "perfect intonation" on a fretted instrument?

...now where is my Peterson Strobe.....?

[Big Joe]

I should all a couple things to this post. First, the Gibsons made in Nashville used the Cumberland Acoustic Bridge. There were a couple issues with those. Until later in 03 the bridges were often fit with a forward slant of the base. This was not really intentional, but the jig used for the bridge fitting was worn and left the base cut where it leaned forward. Pulling it back did not resolve this issue. We did discover this and fixed many bridges. This finally allowed them to sit as they should. If your mandolin is 03 or before you may check that out and if it leans forward get it checked out and refit if needed.

Second, we realized the A strings were having some issues and worked with Steve to get the intonation points as good as possible. The work on the bridge made them far better, and actually better than the original. This was later in 04 and the bridges on the late 04 and after are a better bridge than earlier ones. We used CA bridges exclusively and they are great bridges. Steve is a very sharp guy and easy to work with when there is an issue discovered. Intonation corrections are always an issue we attempted to deal with as much as humanly possible.

At the Big G we had not only technological advances to consider, but the historical aspect as well. Charlie was always going to keep things as Loar like as humanly possible but that did not preclude use of modern technology except where old school was needed to achieve what was going to produce the most Loar like results in his mind. There were a few advances we could have implemented but would not leave the product truly Loar like. The main issue was the tailpiece. We would loved to have used the James tailpiece. Bill is an absolute genius in that design and it functions as well an anything I've seen without leaving the tradition out of it. I do congratulate Bill for that. However, it was too far from the original for Charlie to use. We did talk about it quite a bit and he even used one of Bill's tailpieces on his personal mandolin. I am glad I am not bound by any particular rules for what we build in our shop. We have the liberty to experiment without the same constraints. Still, after so many years with Charlie, it is hard to deviate very far from the real model. Maybe just a bit....let's see what comes out a bit later in the year :) .