Acoustic Intonation


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EdgedInBlue
03-02-2008, 07:52 PM
I have an Ibanez VCE70 with a fixed bridge. I have an intonation problem on the 12th fret and unless I'm literally pressing the string into the fretwire I don't get the rich full sound of the note. I'm a poor college student and I need a cheap fix. I've had a couple people tell me that I should just tighten my truss rod. I'm willing to do that, but I want to know if there's any other ways.

LeftyDave
03-02-2008, 11:28 PM
Well, unless you want to make your guitar unplayable, DON'T TIGHTEN THE TRUSS ROD! The people who consistantly suggest this step as a first cure for action, intonation should not be posting. They do not know what they are talking about.
Intonation is simply the guitars ability to be able to be in tune along the entire length of the neck, and is directly related to scale length, not neck relief such as is the case with the truss rod.
If you need your acoustic intonated, I'd suggest you bring it in. Acoustics aren't as easy to adjust as electrics. Sorry, I realize you're on a tight budget being in college and all, but it's just the way it is. You can do another cheap fix tho and that's trying different gauges of strings. If you used to have say a set of .012's on it, and now you have a set of .011's and it's not intonated, then maybe going back to .012's will fix it. Acoustics are intonated initially at the factory with the recommended gauge of strings that the Mfr. suggests. Changing them can and will change the intonation.

johnos
03-04-2008, 04:33 AM
Agreed.
Truss rod is not the way you need to go. Common misconception, people think you can use the truss rod to fix all sorts of things. I would take it in to a decent repair dude/luthier.
Acoustics aren't as easy to fiddle with and are harder to fix if you stuff something up. I wouldnt recommend stuffing round with it without having someone show you the first time.

Paleo Pete
03-04-2008, 09:24 AM
The people who consistantly suggest this step as a first cure for action, intonation should not be posting. They do not know what they are talking about.

Couldn't agree more. The mere mention of your guitar's action will get you a half dozen yoyos telling you to adjust the truss rod...which has very little to do with the guitar's action, or intonation. I've seen truss rod adjustment advised on here to adjust intonation too, sometimes I think these people don't even know what intonation IS...

Intonation on acoustics cannot be adjusted without removing and relocating the bridge, scale length is set and fixed during manufacture, intonation can't be changed without also changing bridge location.

The most common cause of intonation problems with acoustics is dead strings. Electrics too for that matter. I very recently "fixed" the intonation on a local player's strat by simply putting on new strings. Since intonation was the complaint, I checked it on a tuner. 2 years after I originally set it, the intonation was still perfect with new strings.

Intonation doesn't sound like your problem though...

I have an intonation problem on the 12th fret and unless I'm literally pressing the string into the fretwire I don't get the rich full sound of the note.

1. it's only on the 12th fret?
2. "rich full sound of the note" makes me think either dead spot or fret buzz.

Look down the neck, from the tuning head. Looking right down the side, do you notice a slight hump at about that point, near where the neck joins the body? That's a fairly common problem with set neck guitars, mainly due to wood shrinkage caused by loss of moisture I think. It will cause the frets at and just before the hump to buzz on other frets, also often will cause the note you hear to be a higher note than the one actually fretted. That's because the frets at the hump are higher than the ones closer to the nut, when you fret a note the higher frets touch the strings before the note you actually fretted does.

This hump is really tedious to fix, and I'm not sure if it can be completely fixed at all. With my Takamine, I've had to file just those frets to somewhere close, recrown them, adjust the truss rod several times, (it also had a bad upbow instead of the backbow it should have) and change the saddle height to get rid of the buzz and wrong notes caused by that hump in the neck. If it weren't the best sounding and playing acoustic I've picked up in 10-15 years, I'd have sold it and looked for another one 5 or 6 years ago when I first started trying to fix it. (I didn't notice the hump when I bought it, didn't look close enough, if I had it would have stayed on the rack. The upbow is probably why it wasn't noticeable. I knew I could fix the neck relief easily...) That explains why the action was high when I got it though...

EDIT: Almost forgot, if this is only happening at the 12th fret you may have one high fret. That can be fixed by either lightly tapping the fret down into its groove with a wood block or filing the one fret down, whichever is needed after closer inspection.

GC Shred Off
03-04-2008, 05:24 PM
Why all this hate for the truss rod? An over or under-stressed neck could certainly be part of the issue. Sight down the length of the neck from the headstock. If the neck is straight, the truss-rod should be all set. Don't play around too much with it. It wont fix the intonation, but it does manipulate the action to some degree and could improve the issue.

My best guess is a faulty 12th fret (either popped up, or needs filing). Have someone take a look at it for you.

LeftyDave
03-05-2008, 08:19 AM
^ You haven't been a member of this community since 2005 either. Also, it's not "hate" for the truss rod, it's simply the fact that the truss is too often cited as the first adjustment to be made for the majority of acoustic problems. The truss should only need to be tweaked seasonally, with more extreme changes in climate, such as from winter into summer, or from summer back into winter. So spring and fall would be the best times. Some guitars may never need it adjusted. It's all based on the individual guitar, and should not be thought of as a one stop fix all. Sadly, there are too many posters in these forums who think just that, and blindly tell other's to crank away on their own truss rods, without knowing the possible outcome of such an endeavor. Those of us who do know how acoustic guitars are made, and who acknowlege the ignorance of those new to the world of guitaring, are simply trying to steer people in the right direction.
In my previous post, I was replying directly to the threadstarter because they were directed to "tighten" their truss. As you may or may not know, tightening a truss rod will provide less neck relief, not more. If a slight buzz is found to be caused by insufficient neck bow, then loosening the tension on the truss would be the right way to go, as this would allow the string tension to pull the neck inward, toward the strings, thereby providing more relief.

Ashbory4
03-05-2008, 10:40 AM
Couldn't agree more. The mere mention of your guitar's action will get you a half dozen yoyos telling you to adjust the truss rod...which has very little to do with the guitar's action, or intonation. I've seen truss rod adjustment advised on here to adjust intonation too, sometimes I think these people don't even know what intonation IS...



I'm thinking about this very logically, I haven't tried it nor have I messed much with truss rod but I think they can be part of the cause of some intonation problems.

Think of the neck and strings as a bow and arrow. If you take the string and press it to the bow close to the tie downs on either end you only have mayb an inch or so for the string to travel before it hits the bow. This will increase the tension of the string a little.

Now if you try to push the middle of the string to the bow you will have a long ways to go and the string will signifigantly increase the tension.

Next, if you did this with a bow that was more strait than curved and pressed the middle of the string to the bow then it wouldn't change pitch as much.

I just used the bow as an example for emphasis on the curved neck.

My point is that if the action on a guitar is high then the string will bend a little because of the distance it has to travel to the fret makes the string tighter. Changes in intonation because of truss rod adjustments will be more noticeable at the 12th fret than the 1st fret.

So to me a truss rod can adjust intonation problems. Comments?

LeftyDave
03-05-2008, 07:00 PM
^ Since you quoted Pete in your above post, I won't reply too much. But here's something for you to think about in regards to your theory of how a truss rod/neck works. Remember that the base of the neck is fixed in place, not free to move about with changes in the tension of the truss rod and/or strings. What about the headstock end? Is that "fixed" in place as well in relation to the tension made by the truss rod and strings, or does it flex back and forth? Just a little food for thought for you.

Ashbory4
03-05-2008, 09:05 PM
^^ Well The headstock will move around with the neck because its atatched to the neck, but the string is attached to the headstock so I would consider it a fixed point from the strings perspective but not from the perspective of the guitars body.

I'm not really sure why you said that.

LeftyDave
03-06-2008, 08:50 AM
And on your bow and arrow analogy? Where on a regular bow, not a compound, is the string attached? Right at the end yes? And each end is free to flex with changes in tension to a) the string and b) to the bow itself.
If you're following me, you'll see why this is a bad analogy to use in relation to a guitar neck. Yes, the headstock will flex a little, but not in amounts that matter as much when it comes to intonation. The mid section of the neck is where the in/out movement will occur, because of the bottom end being fixed in place to the body, and the design, placement of strings, tuners, nut and end of the truss rod for the other. That almighty truss rod isn't going to make the neck stretch out as it would if you were to push in on the back side of your theoretical bow, because the ends won't allow it, nor will the rest of the neck due to design. What it will do however is create a smaller bow shape, along the length of the fretboard, with the greatest flex being in the middle of that curve.
Ok, so back the gist of the issue here. Will adjusting the truss rod affect intonation? Of course it will. Will it effect it enough to correct intonation issues? Depends on how badly the guitar is off. Is the truss rod the correct place to adjust intonation? No. The saddle/nut placement is, and is done by lengthening/shortening the scale. The truss will only move the nut end in or away by small increments (it's at the end of that pretend bow remember), so intonation will be changed only marginally. In what order should a guitar be setup, i.e.; neck relief, action, intonation, tuning? This is a bit harder to describe, but since each effects the other, they are actually done in steps. Each is first "roughed" in to bring that particular adjustment close, then move on to the next. A luthier will backtrack to a previous step in order to assist with the current one if he needs to until each is set properly, with the obvious fine tuning last to bring the guitar to concert pitch.

anita prs bad
03-06-2008, 03:10 PM
so glad my taylor was just to my liking from the factory just a touch up on the b string groove in the saddle is all it has ever needed not to bad for a "guitar i wouldnt even look at in that range hehe". Listen to Lefty he is as smart as ive seen here i think he may actually no what hes talking about.