How to Get Perfect Intonation on your Guitar

18 Oct

We were getting to the final stages of building this guitar – putting in the frets and making the bridge.

Once again we got onto the subject of perfection – the quest for it and its unnatainability.

I met a friend I hadn’t seen for a while the other day and asked him how he’s doing. ‘I’m doing the best I can. How ’bout you?’ he replied. ‘Bout the same’, I said.

Back to the subject of guitars, my student was getting concerned that his guitar won’t work properly. What if the frets aren’t perfectly aligned? What if they’re not where they’re supposed to be? What if the bridge is too far back, or forward? How do you know what the right angle is for the saddle?

Strangely enough (especially for a world famous guitar maker!) I’ve never really given these questions too much thought. Obviously, the same thoughts cross my mind when I’m making a guitar. As I mark out the fret positions I know that if I get it wrong the notes will be in the wrong places which will make the guitar almost impossible to play in tune. If the bridge is in the wrong position all the notes will be out. So I try to get it right. I calculate the fret positions to the nearest 1000th of a mm. Then using a steel ruler and a sharpened spike I mark their position on the ebony as best as I can. The thing is, my steel ruler can measure gradations of 1mm. My eye can focus on the space between one millimeter line and the next, and my hand can guide the sharpened spike to the closest estimation of the right position.  For instance, the first fret should be placed 36.482 mm from the nut. Even if my spike was sharpened to a point a few atoms across, my eye would not be able to differentiate between  one thousandth of a mil and the next, besides which, my hand would be shaking too much to mark it that accurately. That’s not a judgement on my poor eyesight or the amount of coffee I drink. Some things are humanly possible, some aren’t. So what do I do? I take a close look and then put the spike into the wood just a little to the left of what looks like halfway between 36mm and 37mm.

Sure, if I had some microscopic, digital, laser-guided computer controlled cutting machinery in my little workshop, I could probably do a bit better on accuracy there. Then again, it wouldn’t  really be a hand made guitar if I used that sort of thing. Well, maybe it could be, in a sort of modern sense – but that’s not really where I’m at anyway. I prefer to make guitars the old fashioned way.

The point is this: The guitar is not a perfect machine. It is a fine balance is between a wide variety of compromises. You will have to tune your guitar. Learn how to use your ears. Those digital tuners are unhelpful. Even if your guitar is a state of the art, carbon-fibre, computer-guided, laser-machined, robot-finished, high precision sound-box with NASA technology graphite strings etc… you will still have to tune it. As far as I know, there has never been a perfect machine. If there ever has been, I’m fairly sure it wasn’t a guitar. Possibly a bicycle. Even a formula 1 racing car needs it’s engine tuned every so often.

Here is a little story about three guitar makers I know and a well known musician. I’ll call them by their initials in order to avoid libel. C, K and O are the guitar makers, J is the musician. C is the most famous of the three luthiers. His guitars sell for around $30,000 and he seems to have a long waiting list. I say ‘he seems to’ because as well as being a very fine luthier, he’s also an excellent salesman (which is also an ancient craft, not to be underestimated).  His workshop is very large, well lit, clean and equipped with the finest hand tools, the latest technological innovations in power tools and an shiny Italian coffee making machine. His guitars are built using excellent, rare timbers as well as modern materials. He has developed a style of bracing his guitars that is so new and innovative that he is considered to be a guru of guitar technology.

One day, J decided to buy a guitar from C. Being a somewhat well known musician, he was able to jump the waiting list as well as get a sizeable discount on the $30,000 price tag on his guitar. He played the guitar for about a year, but try as he might, he could not get it to play in tune when he was performing under hot spotlights, changing from playing in E minor to playing in D. This had never bothered him before, with his old guitar – he would retune in between songs without even thinking about it – but somehow it irked him with the new guitar. He repeatedly took the guitar back to C to remedy the problem, but C repeatedly refused to touch it, saying that the guitar was perfect – the problem was with J, the player. After a year J sold the guitar (to a collector, for $60,000. After it had been owned by him it was ‘collectable’) and reverted to his old guitar.

Some time later, still (as always) on the lookout for a new guitar he went to K. K is well known for making the most flawless guitars possible. They are simple and traditional and extremely neat. Before becoming a luthier he spent many years designing components for the electronics industry. Let us say that precision is his talent. ‘Unlike some guitars’, he says ‘ my guitars do not impose themselves on the player. They are like a blank canvas waiting to be filled.’

When J collected his new guitar from K, he was immediately impressed by the clarity of the sound, as well as the neatness and orderliness of K’s small, clean workshop. He was pleased at how the guitar stayed in tune, even under testing conditions, but it somehow left him feeling empty and alone in a way his old guitar somehow didn’t. When, after a year of playing K’s guitar, he found himself with song-writer’s block, he sold it (to a music professor who was extremely pleased with it) and reverted back to his old guitar.

Later that year, by chance, J came across O. O is a fairly unknown luthier who specialises in accurate reproductions of historical instruments as well as carrying out detailed research into all manner of areas relating to musical instrument making. At the time he was living and working in a small attic room above a butcher’s shop in a little known English market town. He lived with his wife and two small children. His ‘workshop’ was a chaotic mess consisting of several unfinished instruments strung up on a rope across the window, Japanese waterstones and handmade  plane blades piles up next to the sink along with the washing up. Jars of varnish on shelves next to jars of jam. His workbench was also the kitchen table. What I remember about the place was the distinctive smell of dirty nappies and animal  glue. And the amazing guitars strewn about the place.

At the time when J met him, O had just finished building a perfect reproduction of an original Torres guitar that he’d been able to measure, map the soundboard thickness and bracing and examine the construction and materials. It had taken about a year and a half to make and was probably the most exact reproduction  of a Torres guitar ever made. J was not really a connoisseur of Spanish guitars, being more of a song and dance man, but when he played on that guitar he was (in his own words) ‘blown away’. At the first note he played, he felt the guitar come to life and his whole being was consumed with the need to make music there and then.

He stayed there for six hours, being unable to put the guitar down and would have stayed longer had O’s youngest child not accidentally drank a cup of oil-varnish and had to be rushed to emergency. J contacted O the next day saying  that he was willing to pay whatever price O asked for the guitar. O named a ridiculously low price and told J to come back in a month when he’d finished varnishing it.

One month later J came knocking on O’s door (O’s phone had been disconnected) only to find that the guitar had been broken beyond repair when the rope holding it had slipped and the guitar had fallen out of the window onto the pavement below.

J went on to write a song about that guitar (substituting the word ‘guitar’ for ‘woman’ and giving her a name) which, for a time was often played on the radio and MTV. This brought him enough money to buy any guitar he wanted, but as far as I know he’s still playing the same old guitar.



3 Responses to “How to Get Perfect Intonation on your Guitar”

  1. sean October 19, 2012 at 5:08 pm #

    Its poetry,romance,comedy, sad silliness of life- like a french movie. I hope O carried on making great guitars and being appreciated for his passion and able to provide for his family and art.

  2. g weigert handmade guitars October 19, 2012 at 5:55 pm #

    Thanks Sean. So do I.
    Here’s an interesting discussion going on on Linkedin ‘The Guitar Forum’ in response to this post:

    scott baxendale • A fixed pitched instrument can’t have perfect intonation, only trombones and fiddles can have perfect intonation.

    Guitars aren’t perfect which is a good thing.

    Wim Stout • It is possible if you know the string height and pull of each string, you can adjust your fret position a little if you knwo how hard a musician frets his string. Further more you need to compensate for each string its position based on the distance on the fret board for each tone.

    Played a model from a Dutch (Israelian origin) luthier once for 2 minutes. It sounds really pure, much more than we are used to.

    But it makes no sence for an instrument that is played in conjunction with other string players because they will always sound out of tune towards you guitar unless they also have such a guitar.

    All the factors to make the guitar and the fact you can only play it solo makes it a unique instrument and may be suitable for some classical music or singer songwriter. he or she must be a good vocalist as well as the human timbre might not benefit from a pure tone. Think about a classical performance, whent he vocalist is only slightly of key, next to the horn section and frettless instruments, it is magnified on the ear.

    Only suitable for the best and requires new playing skills as the frets might not be where you have them on other guitars.

    High learning curve I think but way to academic for me.

    But hey, go for it, it is possible, just a lot of math involved.

    scott baxendale • A guitar, piano or any other fixed pitch instrument will sound out of tune if it is tuned to perfect pitch, which is why they have what is called “tempered” tuning. If you tuned a piano to perfect pitch with a strobe tuner it will sound out of tune, so they use a system of perfect fifths. Same with a pedal steel, you have to adjust some of the strings a few cents away from perfect to sound in tune. Frets are placed in positions that give the best average and therefore it will never be able to be tuned to “perfect” intonation. Only a fretless guitar would have that ability.

    Gideon Weigert • Thanks for your comments, all of you. That was just about the point I think I was trying to make – only you all said it far more precisely.

  3. Roland October 22, 2012 at 9:18 am #

    Nice article Gid, and a lovely story! Itching to know who J was 😉

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