Martin Guitar String Height Specs

A Reader Asks about Martin Guitar String Height Specs

I’m making a decision to buy a D28 authentic 1941 but some question happen in my mind since this guitar has no adjustable truss rod. What about the action (guitar string height) of this guitar and playability?

How about the action at fret 12th of the sixth and first strings?

Thank you.

– Kanarat, Thailand

Spoon Writes:

Thank you Kanarat for this very good question. The D-28 Authentic 1941 is by all accounts very comfortable to play. And that includes my own opinion. Guitar string height can vary within Martin factory specs.

Martin dreadnoughts with “factory action” tend to have slightly higher action than some other modern guitars. This is particularly true with vintage-style Martins.

The Martin guitar factory considers a low ‘E’ bass string to be within specification if the distance from the 12th fret to the bottom of the low E string is between 2.38 mm (3/32″) minimum, to 2.78 mm (7/64″) maximum.

The high ‘e’ treble string should measure between 1.59 mm (1/16″) and 1.98 mm (5/64″) at the maximum.

I have not measured one myself, but I would expect these guitars to come in the middle range, near 2.45 for the low E bass string and 1.86 or so for the high e treble string. That would be with medium gauges strings. Light gauge strings may make the action a little lower, if one replaced mediums without doing any other other adjustments.

Personally, I rarely notice action unless it is abnormally low and buzzy, or abnormally high so intonation and degree of difficulty in the highest frets becomes apparent.

But since you would be acquiring a Martin from overseas, with a glued in saddle and a non-adjustable truss rod, I would recommend you ask the dealer you are buying it from to get an accurate measurement for you, or even ask them to adjust the saddle height to meet your specifications.

And that is one man’s world on…

Martin String Height Specs

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21 thoughts on “Martin Guitar String Height Specs

  1. Great website and very informative on readers experiences with Martin guitars. My 1995 Martin HD 35 has been nothing but a problem child since purchased new. The truss rod is frozen and the low e is fully 4/32 above the fret board at the 12th fret..nearly impossible to play fingerstyle. I bought a pak of new bone saddle material from the Martin 1833 shop and lowered it to playable height by making a new saddle…easier to play but considerable difference in tone experienced. String angle at the bridge changed I guess the tonal quality.

    1. I am sorry to hear this, James. If this problem existed at the time you bought the guitar, the seller was responsible for getting it fixed via the lifetime warranty. Frankly, if the truss rod was frozen Martin should have either given you a new guitar or taken the fingerboard off and put in a new rod, or something to that effect.

      And you should still be able to take it to a certified Martin repair person. There may be some issue given how long you have had the instrument, however, if there is no evidence of the problem existing when the guitar was new. But it is worth checking out. Martin has changed policy in recent years regarding what voids the warranty and what does not. But if things are as you say, they should have taken care of the issue a long time ago. And they may still be willing to under your warranty. If not, you may be able to find someone who really knows what they are doing to fix the issue – which may require a neck reset, but would be worth it in my opinion. Good luck!

    2. Thank you for your reply which I just read 8/26/2018. I am going to ask Martin to fix this truss rod problem …two luthiers would not touch it after making initial attempts to loosen the truss rod. I can’t play or enjoy it like this as I cannot use a pick. This is a great informative website.

    3. @James…

      “String angle at the bridge changed I guess the tonal quality.”

      Not so much. What changed the tonal was the intervallic harmonies that the string sings at it’s height over the 12th fret, where the harmonic value heavily influences the sound.

      Moreover, in filing the saddle, you took away from the overall mass of the bridge, that action leaving it in a different tuning than it had been before.

      To help that out, you can add a little shellac with a tiny brush in the area of the bridge under the strings, between the saddle and the pins. Add a gentle stroke of shellac under each string, and then tune the strings back to pitch.

      Keep doing that process until the warmth and depth your lost largely returns. (It won’t entirely return because you still have a different string height (harmony being sung) at the 12th fret than before.

      You could easily do that process for 8-16 times before you recapture most of what you feel you lost.

      Always wait at least 4 hours after applying more shellac to shell – IF the shellac is fresh. If it comes out of a can, you might have to wait several days between each step, as shell loses it’s drying capacity in cans, more and more the longer it is in the container.

      1. Thank you, Ivan. That is a profoundly dedicated tone lover right there! I have known countless guitarists who lower their saddles and never consider what influence that may have on the voice of the instrument, and with most if not all of them noticing to change at all. But when someone does notice a change for the worse, this would be a viable solution.

  2. Hi – Thanks for the info on Martin specs. Just wanted to point out that with regards to action (string height over 12th) and string guage, you got it backwards – Light strings require higher action as they vibrate in a wider arc.

    1. Thanks, weeasle

      The physics as you state them are correct. But I did not mean one should make the action lower for light gauge strings.

      I should have been clearer in my choice of words. When I said “light gauge strings should be a little lower” I meant that if one takes off a set of mediums and puts on a set of lights without doing any other adjustments, the string action will likely be a little lower.

  3. I bought an OM28A and the saddle is 0.09″ off the bridge which seems on the low side. The action at the 12th is a hair over 6/64 and 4/64 which is on the high end of factory action setup. Does this seem right?

    1. Dave, where are you measuring the saddle?

      The action is the correct height. Martin aims for 6/64th from the top of the fret, and to the middle of the string would be a 1/32nd higher

    2. 6/64 and 4/64 is not on the high side. That’s the low side. A 3/2 action. 3/32- 2/32. Perfect action honestly.

      1. Not according to Martin. I assume it will not void a warranty to have action out of the official specs, but they are what they are. I too prefer higher action.

  4. Super info. thks. Just found your site as I too, had some questions about action. I have a Martin D-28, manufacture date late 2013 and I purchased new in Feb. of 2015. It has always been humidified and kept in the case. I only really noticed the ‘high’ action when I changed to drop D tuning and I noticed amplified ‘string whip’. I estimate the height to be 4mm. I re-tuned and looked again and the action is noticeably higher than my Epiphone EJ 200 and Simon & Patrick Woodland Folk. I think, as you have said, the guitar is just getting acclimatized to it’s ‘new’ home. Play ability is still good, (although the player needs work!) but I think I will take it back to Folkways Music to have the Tech take a look. Thks. Great site, I will bookmark it!
    from Canada
    Martin D-28
    Epiphone ej200
    Simon&Patrick Woodland Pro Folk
    Greg Barret D7 CE
    Washington Rover

    1. Well, if it is really 4mm that is way out of spec and you should have it adjusted. If you are the original owner you should be able to have this done for free, so long as you take it to a certified Martin repair person.

      My normal answer regarding string height is “what ever a particular player likes is the correct action.” But it sounds like yours is more than twice the maximum string height considered within Martin factory specs.

      Welcome to One Man’s Guitar, Bryan! And thanks for your participation.

  5. Hi,
    on 2010 i purchased D16-GT, it plays great, but in 4 years i noticed higher action (i.e. 3 to 4 mm on 12th fret) and on backside of the neck could be seen a very little (i.e. 0.1 to 0.2mm) bubles in the lacquer, particularly in the wood lines. Is normal, that guitar will “settle”in some years and i’ll have to readjust now somehow?

    1. Mojek,

      It is not normal to have bubbles in the finish, but it is not uncommon. I had a Collings OM-1A that had one rather large bubble in the finish.

      It should not be a point of concern, unless it increases. Certain substances can disrupt the finish (like insect repellent for example) and that can result in the finish melting or getting soft, and sometimes blisters and bubbles can appear. That is quite different than an air bubble that was trapped during the finishing process.

      Acoustic guitars are under a lot of stress from the tight strings. So action will change over time. I would recommend finding a good repair person to see your guitar and possibly adjust the action for you. That is often simple to do, either through adjusting the rod in the neck, or adjusting the height of the saddle, or both.

    1. Hi Ben,

      As I tried to point out, what is high action is based on personal taste for the most part. Also, Martins traditionally have higher action than many other manufacturers. But unless it is a true defect in the particular guitar, from wood swelling or shrinking, etc. action is easily adjustable, but it is recommended that you have a certified Martin warranty repair person do that, unless you are comfortable with such adjustments.

  6. I took delivery on my 1941 d28 authentic on feb 6th 2014 now seven months later I have sent it back to the factory because the top has lifted up and the action is up . when you lay a straight edge on the neck it does not clear the top of the bridge now. They think it is due to high humidity I am not sure.

    1. I am sorry to hear this, Andrew. Rear shifted bracing should help protect against the kind of top bulges normally seen behind the bridge. Unfortunately, when it comes to guitars made by hand out of organic materials like thin, solid wood, some pieces of wood will misbehave. The old saying is a guitar takes about two years before the wood stops trying to turn back into a tree.

      I hope Martin will be able to set things straight for you. I would be careful signing off on any blanket assessment blaming over-humidification, as that might void the warranty. Good luck with it!

  7. So, for someone who likes a nice low action, would it be more appropriate to purchase a non-authentic model? Not sure if most dealers have the expertise to adjust these beautiful D-18 and D-28 Authentics. I think this is a great topic to discuss. Thank you very much for your valued knowledge.


    1. I cannot really answer that question objectively. I tend to notice action as being too low more than I notice too high.

      But I would certainly trust any of the major dealers that are true guitar shops (as opposed to a big box store like Guitar Center) to know what they are doing, as they have spent years doing adjustments and repairs on vintage Martins in addition to modern ones.

      I should also add that I said I expect the Authentics to come in the medium string height range, because they are trying to replicate the kind of vintage Martins coveted by Bluegrass musicians, who are either used to or seek out slightly higher action compared to modern guitars. There are exceptions of course since Tony Rice and Robert Shafer both prefer action so low it is practically resting on the frets.

      Martin factory action was traditionally higher than that used by makers like Taylor. Bob Taylor made his bones by offering acoustic guitars that felt and played like electric guitars. Martins had thicker necks, and higher action often called “Bluegrass action.” If you pick very hard, or do a lot of heavy hammer ons, lower action can be more of a problem if you want clean or pure notes.

      When Chris Martin took the reins of the company he introduced the modern low profile neck and over time the action came down some too. More recently, the factory invested in a Plek machine, a robotic chamber that measures and adjusts the relationship between the strings and the frets to a very precise measurement.

      I have no idea what the set measurement is for the Authentics, and if it is any different than other guitars. Probably not. But guitars settle during their initial acclimation period and the exact bow of the neck and arch of the top can change. Actually it is almost certain to change some. There have been reports of all sorts of Martins with action reaching up near or over the maximum height within spec. But the same holds rue from brand of guitar that uses organic materials like solid wood.

      It is obvious that the new Performing Artist Series has lower action than typical for Martins, just as the neck profile and width of the fingerboard are also smaller. They have finally caught on that there are now two generations of players who grew up with electric guitars that had fast necks with very low action.

      The Authentics are made like they used to make them, with a non-adjustable neck rod. So any adjustments to lower action have to be made at the nut or saddle or in a neck reset of the dovetail joint.

      While high action is a concern, I see more people on guitar forums who bought Authentics, including the 1941, who say the action and playability is “like butter” more than I see people mentioning high action being a problem. Also, a lot of players rarely go beyond the fifth fret without a capo, so they may not even notice if their 10th fret would seem high to some players.

      But just like buying a Martin made before the 1980s, if you like the guitar enough that you buy and keep it, but want lower action, you or someone you trust has to take the saddle height down, or put in a new saddle.

      It was also common for people to have a winter saddle and a summer saddle, as they were called, to make up for the flux in humidity and its effect on the wood across the seasons, if they were sensitive to string height. Authentics have a glued in saddle, as did all Martins once upon a time. That usually means the saddle is destroyed in the process of removing it, so a new saddle, or two new saddles in the case of a winter/summer set of saddles would be required. But I have heard of people who were able to save the saddle when it was removed.

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