Acoustic Guitar Intonation (1 Viewer)

[Michael Pineo]

Hi Everyone,

Having played electric guitar my whole life, I am unfamiliar with adjusting the intonation on an acoustic guitar. I just bought my daughter a half-sized acoustic, because she has been bugging me to teach her how to play. My guitar is too big for her, so I figured a half-sized, practice or travel guitar would be perfect. The size is perfect, but the intonation is horrendous. I am familiar with setting up an electric guitar, but the acoustic guitar doesn't have separate saddles that I can adjust with an allen wrench. Is there any way to adjust the intonation on an acoustic, that doesn't require anything major? Or am I just out of luck?

Thanks,

MikeP

 

[Mike Voigt]

To tune each string, the guitar has 6 little handscrews, all the way at the neck of the guitar. Use those to tighten or loosen the strings, thus tuning it.

Set the lowest bass string to 'E'.

Then go from there on the 5th fret: press down the 'E' string and tune the second one to it. From 2nd to third, same thing. From 3rd to 4th, same thing. From 4th to 5th, use the 4th fret!!! from 5th to 6th, go with the 5th fret again.

That gives you relative tuning of each string, but the real problem is when the guitar itself is not built well enough to where those actually match their tones. A decent option there is to use an electronic tuner, you can play a note and adjust it for sharp or flat. However, that does not handle the situation where the frets themselves are in the incorrect spots...

Good luck! I enjoy playing the guitar, though I certainly do not claim expertise. It is, however, a very relaxing instrument to play, and good for anything from campfires to concerts.

 

[Carlo_M]

Mike, I believe Michael is talking about intonation, not necessarily tuning. The acoustic guitar repairman I talked to said intonation can be heard by playing the 12th fret harmonic of a string and seeing if the fretted 12th sounds just like it. Perfectly intoned guitars will have the 12th fret harmonic and fretted 12th note sound identical.

He checked mine and found it spot-on and so I didn't get to see what he would have done to correct it if it was off.

Sorry.

 

[Mike Voigt]

My bad, misunderstood that one. Hope it helps anyway!

 

[Michael Pineo]

Thanks for the replies guys. Yes, after playing for 17 years, I have figured out how to tune a guitar

I did some searches online and everything I have read seems to indicate that adjusting the intonation on an acoustic is not very easy. Instead of adjusting saddles like on an electric guitar's bridge, the articles I have read discuss actually filing down the grooves in the nut, and one guy who went so far as to remove the headstock and shorten the neck on his guitar!

Oh well. I guess I can't expect too much for a $25 guitar. If my daughter is anything like me at her age (and she is, much to my wife's chagrin), she probably won't have the attention span to really learn the guitar yet anyway

MikeP

 

[Carlo_M]

Well shortening the neck would also have the effect of shortening the scale length (with most nowadays being at 25.4" and a few (usually 12 fretters) at 24.9" - but the different scale length will affect your ability to drop/change tunings.

I do believe that adjustments to the nut and saddle are probably the way intonation is adjusted on the guitar. Definitely not a do-it-yourself thing unless you're a luthier/repairman or aspiring luthier/repairman.

Why not head down to your local Acoustic Guitar shop (we have a couple of wonderful ones in my side of L.A.) and see what they charge?

 

[Mike Voigt]

Sorry about that, Mike. I know next to nothing about electric guitars, hence the mistake estimating same for you going the other way. Oh well.

Yeah, what I read goes to those extremes, too. One guy at least had some suggestions on corrections:



Guitar Intonation - Checking & Correcting Intonation

Best of luck...

 

[Michael Pineo]

No need to apologize, Mike. I was just teasing Thanks for that link. That is one I hadn't seen.

Carlo -

Thanks for the suggestion. I think I'll wait to see how long learning the guitar holds my daughter's attention before I do anything. If it does hold her interest, I may just go down to the local Guitar Center and try out some smaller acoustics myself until I can find one that has better intonation (I got this one through Musician's Friend and had to rely on other people's reviews. I wouldn't normally do that, but it was only $25).

Thanks again!

MikeP

 

[Brion Lydon]

Hey Michael,
Are you sure you are talking about intonation or action? Because all you have to do to intonate a guitar is to tune the string open and then make sure it is tuned to the same note one octave higer(the 12th fret). If you mean action(how far the strings are off the neck) you'll need the bridge saddle filled down a few millimeters. Hope this helps.

Brion

 

[Michael Pineo]

Right. The problem arises when you cannot get the twelfth fret and the 12th fret harmonic to be in tune at the same time. That is where intonation comes into play. I can tune the guitar so that the 12th fretted note sounds right on a particular string. Then I can tune the 12th fret harmonic so that it is in tune, but then the 12th fret note is out of tune (and so on and so on). With my electric guitars I can simply adjust the saddles for each string to make sure that the distance from the saddle to the nut is correct. On this particular acoustic guitar, the saddle is one piece of plastic, so each string can not be adjusted separately. Action does have an affect on intonation, so I have been considering filing down the saddle, but it will have to be trial and error for each string, so I am not sure if that much work make sense on a $25 guitar.

Thanks for the ideas everyone!

MikeP

 

[Carlo_M]

Rather than filing down the saddle, you can also adjust the truss rod (if it's adjustable on your model). Just a quarter turn tighter can make a huge difference...

And truss rod adjustments can affect intonation, which is why they caution not to rely too much on truss rods to adjust action. You can modify action slightly by turning the rod tighter or looser 1/8-1/2 of a turn, but any more than that and you really should look at adjusting the height of the nut or bridge.

 

[Michael Pineo]

Thanks Carlo! I'll check that out when I get home tonight.

MikeP

 

[Tim Hoover]

Michael - something like a compensating saddle should help intonation matters somewhat. One of the guys at Rotosound gave me this lengthy speil about how, due to the obvious differences in string gauges, they will not all stretch at the same rate, thus affecting intonation somewhat. A compensating saddle, with its offset saddles for each string, ummm....compensates for this

LOL...I don't know how scientifically accurate that is, but the compensating saddle does seem to help a bit. And, it only costs a buck or two...

 

[Tim Hoover]

I just asked a buddy of mine, who is a guitar tech w/ Staind, and here is his advice:

He said that most intonation problems can be removed through careful adjustment of the truss rod in the neck, although larger problems may require popping off the nut or saddle and shimming them. Shimming the saddle is obviously easier as it's not glued down

He also adds that the 1/2 scale guitar may never have complete intonation. He says that the longer the scale length, the easier it is to get proper intonation. FWIW...

 

[Michael Pineo]

Thanks for the info Tim! I'll look for more info on the compensating saddle.

I kind of thought the smaller scale of the guitar might adversely affect the intonation, but I hope to at least get it to an acceptable level. It is really bad right now. Even chords in the same position are off (I can tune the guitar to give me a nice open G Maj and the open Em will be out of tune).

Thanks again!

MikeP

 

[Carlo_M]

This may also be (in addition to intonation problems) a fretwear problem, or fret misalignment, or scale length issues (as in the frets aren't all properly spaced) since they used an odd scale length.

Well for $25, at least it plays!

 

[Tim Hoover]

Michael - for another suggestion, simply have the action adjusted. It's possible that it's rather high and fretting the chords is throwing some of the strings sharp. It might be a tradeoff between good intonation and excessive buzzing, though. Another something to look into.

Carlo - LOL...me too, although I kinda DO have my own guitar tech. Whenever my friend is off the road, I ply him with beer to come check out all my guitars. I'm just hoping the Staind guys teach him about drums. I for one would be extremely happy if I never had to tune another tom again......

 

[Michael Pineo]

That's pretty much what I was thinking

Thanks for all of the responses guys. It's pretty impressive that you can ask just about anything here and someone will have an answer.

Unfortunately, my wife wrapped the guitar, so I'll have to wait until after my daughter opens it tomorrow to do anything with it. IIRC, the action was a bit high, so maybe just that adjustment will improve the intonation a bit.

Well, Merry Christmas, or Happy Festivus, or whatever everyone celebrates!

MikeP