Why is it the fiddle that it is? I guess the physics is that if the length of the string from the nut to the 12th fret is the same as the length from the 12th fret to the bridge saddle then the intonation should be spot on. However the reality is that simply doesn't appear to be true. I have an old Strat that if you set up, say, the A string that way it is noticeably sharp at the 12th fret and even worse at the higher frets. The saddle actually needs quite a bit of adjustment to get the intonation correct. And yes I did measure with the string held down at the 12th. I'm guessing the width of the fret wire and the radius of the saddle all contribute?
I play guitar because I enjoy it rather than because I’m any good at it
Comments
Part and parcel of a fretted instrument. Look at microtonal guitars and imagine intonating those!
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
each string, even when it's exactly the same claimed (if you took 20 "9s" you'd probably find some that were 8.5, some that were 9.5) thickness, intonates slightly differently.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
Ringleader of the Cambridge cartel, pedal champ and king of the dirt boxes (down to 21)
They should all be the same, and 24th fret too.
So, a high e, would all read e at 0/12/24 fret, and 12th fret harmonic, if not the intonation is out.
edit, I should have said the tuner reads e and is dead on, if it reads e (or other than e), but the gauge is off centre on any position then the intonation is out.
It would be much easier to show this than write it.
Ringleader of the Cambridge cartel, pedal champ and king of the dirt boxes (down to 21)
Supportact said: [my style is] probably more an accumulation of limitations and bad habits than a 'style'.
If the frets are out then surely setting the intonation is (a) impossible (whereabouts on the mis-fretted board to you want it to intonate correctly?) and (b) the least of your problems!
Supportact said: [my style is] probably more an accumulation of limitations and bad habits than a 'style'.
Or: T/A = E s / l
(2fl)^2 = T / rho = T / (A d) = E s / (l d)
l length (ignoring different scale and string length for simplicity), T tension, s string extension, A cross section area, d bulk density, rho length density, f frequency.
Do you mean 12th fret harmonic and open? 12th fret harmonic and 12th fret can be different, since 12th fret harmonic is in the middle of the string speaking length and 12th fret itself is not necessarily (which is why you're adjusting intonation). 12th fret harmonic and open should be the same, though I've seen them different with old strings (not sure why, maybe stiffness or accumulated dirt, one reason to use fresh strings for intonating).
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
I do the standard 12th fret harmonic compared to 12th fretted note, but I also check 5th fret against 17th fret quite often too. tune to make the 5th fret note in tune (ignore if open string is in tune or not), adjust intonation till 17th fret also plays in tune
the first check is usually best and all you need to do if you know your guitar is set-up right already. if all is good setting one way will mean the other is fine anyway
the 5th and 17th fret check helps to see for nut or fret placement issues. nut issues are way more common and much easier to fix than fret placement issues.
occasionally you come across an old guitar with issues and you have to balance between the harmonic/12th fret method and the 5th/17th method to get something that plays mostly in tune over most of the fretboard - without modding the guitar
compensated nuts change the rules a bit too, genreally the string needs less compensation with these.
Instagram
no, the point of intonating a guitar is to get as many of the notes on the fretboard playing in tune as possible.
getting harmonic and 12th fret to the same pitch is one way of measuring this. one way that works well most of the time, assuming everything else is set-up correctly
if you have the time you should go through every note on your guitar with a tuner, you will start to see how inaccurate it really is
Instagram