Official Luthiers Forum!

Hello, I'm a player with 0 lutherie skills and I'd like to learn some more about my instrument. Just in case any of you guys are registered on two or more lutherie forums, this will be the second time I've posted this request in order to cover my bases. So please, any advice is welcomed.

There's so much to learn so I'd like to start with one area: intonation - and there's so much in just that one area. It seems impossible to get proper, or close to proper, intonation if you were to directly replicate the position of notes on a string onto a fingerboard when building a guitar neck. There's so many things that in my mind would change the 'true' position of the notes and therefore intonation. Here's one example of those things..

Neck relief. Neck relief alone would affect intontion in so many ways. The curvature, or relief, creates different action along the length of the string. This difference in height equals more stretching at different points when fretting and consequently greater change in pitch/intonation. Another thing is the actual position of the frets changes when you bend, or relieve, the neck from its original position.

Anyways, I don't expect anyone to give this detailed a lesson on a forum (but feel free if you want to ), which is why I'm asking for good books on the subject. Keep in mind that I know nothing of lutherie and I'm sure, as in every profession, there are terminology unique to the craft so I really need a book that's friendly enough for a novice but more advanced than any summary I can pick off the internet. Something intermediate-advanced, or I dunno....

Well, sorry about the long post but I really could use your guys' help and I'll appreciate any, thanks.

Hello Ian and welcome to the forum. Your assumptions are correct in that there are many variables which can affect the intonation of an instrument. Before you get too deeply embroiled in them (too much information can be more confusing than none at all...) read this excellent series of articles by Mike Doolin, a gifted luthier and musician. I know that they helped me get centered and improved my understanding of the subject when I was starting out...

http://www.doolinguitars.com/intonation ... tion1.html

Good luck in your endeavor and please continue to ask questions. All of us here will gladly try to help as much as we can.

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Peter

I would say that it's all but impossible to obtain 'perfect' intonation on an acoustic guitar, espcially one with straight frets. As you say, there are too many things that can throw it off. OTOH, no other instrument I know of has automatically 'perfect' intonation either. Pianos, especially small ones, are egregiously bad due to limitations of the strings, and even the mighty pipe organ can't use equal temperament, in part _because_ the pipes are so close to 'perfect'. The higher partials of the lowest notes would beat terribly with high notes if they did.

I address some of the issues with strings in a paper that just got up on my web site:
http://www.alcarruthluthier.com/Downloa ... Theory.pdf
It's pretty involved, but as thorough as I could make it.

Fortunately, most ears don't demand 'perfect' intonation. Good thing, too, or there would be no music.

Dan Erlewine's The Guitar Player Repair Guide, 3rd ed. goes into this subject at length... except acoustic guitar bridge compensation, which he tells you to go elsewhere to learn about.

All the luthier supply houses sell it, as does amazon ( http://www.amazon.com/Guitar-Player-Repair-Guide-3rd/dp/0879309210/ref=sr_1_1?ie=UTF8&s=books&qid=1255457357&sr=8-1 ).

Your library might even have a copy; some of my local libraries have this on the shelf...

I would argue that most ears demand imperfect intonation, which explains stretch tuning and less perfectly, the saxophone.

Sorry, off topic.

_________________
"Building guitars looks hard, but it's actually much harder than it looks." Tom Buck

What makes this subject hard to understand is that there are actually two issues
-Inotation
-Temperment
In simple terms, inotation is getting the fretted string to play the note (frequency) you intend. If this is just getting it to match your electronic tuner, then it is fairly easy. Get your frets in the right place, nut slots low and add compensation length to the string at the saddle.
Playing methods and finger pressure can affect the end result too

Temperment however is a much trickier issue, and is why many say the guitar cannot play "in tune"
Today we almost universally use a system called equal temperment which gives a fixed ratio between semitones. This enables us to play music in any key we like (this was not the case on older instruments)
This however means that some intervals such as the fifth are not the simple mathematical ratio that they should be and can sound off even if both notes are perfect according to the tuner.
This is not an inotation issue, but an issue with the structure of the musical scales we use

Thanks for all the great links, I think they'll keep me busy for some time. Jeff, I'd love to learn a bit more about the differences between intonation and temperament, do you know of any good places for me to start? Thanks again for all the help.

Helmholtz wrote a great book on acoustics in which he covers everything about the subject. He even delves into the reasons why the brain dislikes beats. It's a fantastic resource from a giant in the field of acoustics.

Alan,

This is an awesome article! Thank you as always for taking the time to do all the in depth research you do and for sharing your findings so freely in such a profound articulate manner. You continue to be a great inspiration throughout the lutherie community.

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Bill Hodge


One does not simply, own enough guitars!

There are some interesting bits on temperament and tuning on this site:
FAQ:
http://www.truetemperament.com/site/ind ... go=4&sgo=0

Their story:
http://www.truetemperament.com/site/ind ... go=9&sgo=1

Acoustic guitar with their neck:
http://www.truetemperament.com/site/ind ... go=2&sgo=8

Devin

An interesting read, by Helmholtz, to say the least:
http://www.google.com/books?id=x_A5AAAA ... q=&f=false

Devin

Thanks for the additional links, I guess it's time to hit the books, or websites.