I could kill you

How annoying is it picking up your guitar, tuning it up, strum a chord and have it sound completely off? One of most over looked and skipped part of setting up a electric guitar is correct intonation. Players often ovoid setting up intonation because of the fear of messing up their guitar or not doing it correctly. The fact is that is is not all that hard.  If you are a beginner guitarist this simple set up can be all the world of difference.  Helping you become a better guitarists with out the confusion and frustration of a guitar that doesn’t tune properly.  This article will break it down to you in the most simple, straight forward way possible.

*Skip to the bottom for a summed up, short version if you think you know the most of the process or just need a refresh.

Quick fact on how intonation works:

Every guitar has its own scale length, the overall length of the playable string.  Scale length is the distance between the nut (where it hits the fretboard) and the center of the forward most mounting screw of the bridge.

Another way to find a guitar’s scale is measure from the nut to the center of the 12th fret, and times that measurement by 2.  The guitar will have some “compensation” where the saddle is slightly further from the nut than the scale length, allowing for adjustment of the intonation.

Supplies you will need:

• Tuner - preferably a higher quality one.  You can set intonation on a basic tuner, but will achieve better results with a more precise tuner.  It is ideal to have an accurate tuner with in ± a fraction of a cent.  If a basic tuner is all you got, it’s all you got and its better than leaving it totally out of intonation.
• Screw driver - one to match the screws on your saddle.  Most guitars use a small figure-8
• New set of strings.  Make sure that your nut is cut for the gage of strings you use.
• A Hard pick. I’ve found you can achieve far greater and more precise results using a pick (sorry if you’re not a pick person)
• Patience - Don’t give up, you can do it!

Some factors to consider:

This article will assume that your guitar is in good mechanical shape and you know how to properly tune a guitar. If you have a very beaten up guitar, some things may also affect your intonation. There is a ton of information on the web on how to fix these problems.  Try searching your problem in a search engine, even Youtube has a billion guitar set up and repair videos that are very helpful. I frequent Stewart-MacDonald’s site for free information and great tools.  Make sure that all these problems are fixed and adjusted BEFORE you begin intonation.

Examples of problems would be:

• String action - This is the distance of the string from your fretboard.  Make sure you strings are not too high, causing the length to be longer. You can get very serious about string action, using gages that match the thickness of your strings and setting correct radius.  For simple set up, adjust it to your desired hight, and make sure there is no buzz from playing the first fret and down.  If you want it to be accurate (like it should be), go here.
• Make sure your radius is set for your bridge.  Radius is the curvature of your fretboard. On the bridge, think of it like an arch.  Obviously, if the bridge has a set radius (no adjustment), no worries.  But like on Fender guitar, they have small allen screws that allow each saddle to be raised or lowered.  You can find a great little template to help you set your strings radius here with instructions.
• Worn frets - these obviously can be a problem. **Also take into consideration your fret hight.  If you have large frets, be careful to push the string just hard enough that it doesn’t buzz during inonation.**
• Neck bow - make sure you neck is straight and you do not have too much relief or warpage. This can change the overall length of the string.  And it sucks to play!  I wouldn’t recommend doing any neck relief adjustments if you’ve never done it before, take it to a pro.  You can find a video on neck adjustment/buzz here, here, and explanation here.
• Faulty saddles/bridge can be an issue.  Make sure all screws for the bridge are tight.  If it is seriously worn down, like on a vintage guitar with years of use, consider ordering a new bridge/saddles.
• Make sure your nut is cut for your gage of strings.  For example, if your guitar is set up for 9 gage string and you throw a 12 gage set on there…

Step #1: First thing you should do is throw on a new set of strings. Good rule of thumb is to do the adjustment in the tuning you normally use.  Tuning down or up can also affect the string length and slightly throw the intonation off.  So if you tune in the entire guitar in D all the time, then do the intonation in D.  Also make sure the strings are stretched out (if you don’t do this already, it’s a good practice to slightly pull on the strings a few times after a restring to stretch them out, or give em a few rough strums. So the strings aren’t going out of tune on you while your setting it up.)

Step #2: Plug in your tuner and Tune the guitar with the tuner to pitch, do not tune the first string with the tuner then use the 5th fret to tune the rest of the guitar, It’s out of intonation remember!?!  Use the tuner to tune every string open.

Step #3: The 12th fret=the middle of the scale of the guitar, like we discussed earlier.  All the calibration is done from the 12th fret.

Easiest way is to start from the top E string and work your way down.  Hold down the E string on the 12th fret, careful not to push too hard or light.  You want to push just hard enough that the string will not buzz (pushing too hard can actually make the note more sharp, throwing off the tuner). Play the 12th fret and look at the tuner to see if the note is sharp or flat.  **Use a pick during this process, more accurate notes produced.**

12th fret is sharp (too high) = move the bridge/saddle away from the fretboard. You need to make the vibrating length of the string longer. The reason it’s out of intonation is because the bridge is too close to the middle of the scale.

12th fret is flat (too low) = move the bridge/saddle towards the fretboard.  You need to make the vibrating length of the string shorter. The reason it’s out of intonation is because the bridge is too far away from the middle of the scale.

Step #4: Once you have established if the string is sharp/flat at the 12th fret, you need to make the adjustment from the bridge.  Grab your screw driver.  This is where you will need to gain some experience thru trial and error.

Try turning the screw at the bridge a few turns at a time, re-tune the string, and check the 12th fret.  Repeat the process until the 12th fret plays in tune, on every string.**After every adjustment at the bridge, re-tune the guitar, that is important.**

If it’s sharp: When the 12th fret plays high, you should tighten the screw on the bridge/saddle.  This will force the bridge/saddle back, away from the fretboard.  Again, try a few turns of the screw, re-tune the string, check the 12th fret.  Repeat that process until the 12th fret plays in tune.

If it’s flat: When the 12th fret plays low, you should loosen the screw on the bridge/saddle.  This will force the bridge/saddle forward, closer to the fretboard. Again, turn the screw a few times, re-tune the guitar, check the 12th fret on the tuner and repeat the process until the 12th fret plays in tune.

Once you get a feel for how many turns will effect how the guitar goes into tune on the 12th fret, the rest of the strings go pretty fast.  Now that you have all the strings calibrated from the 12th fret, tune it up and give your favorite chord a strum. If everything went right, it should sound great!

Summed up version:

1. Put on a new set of strings, tune to your normal tuning using accurate tuner and hard pick.
2. play each string on the 12th fret and if that note is sharp, tighten the screw to move the bridge/saddle away from the fretboard.  If the 12th fret note is flat, loosen the screw and move the bridge/saddle towards the fretboard.

12th fret sharp = tighten to move bridge away from fretboard

12th fret flat = Loosen to move bridge towards fretboard

Trouble shooting: If you’ve done this process and still have chords not playing correctly you may want to go back at the top and look at the examples of other problems that can cause a guitar to be out of wack.  If none of that helps, check the scale of your guitar.  Homemade guitars sometimes have the wrong dimensions for the scale, where the bridge is mounted too far or to close for the scale.  Or if the scale is correct on a homemade guitar, they may have cut the frets improperly causing a compound error.  For example, if they laid the frets out by marking with a scribe/pencil and the accuracy is plus or minus 10 thousandths of an inch, they could have been off by as much as 1/8 inch at the 12th fret.  Another issue is your scale may be off due to switching of the original neck.  If your neck has been replaced, check your scale length by measuring from the nut (where it meets the fretboard) to the center of the 12th fret and times that by 2.  Then measure from the nut to the bridge, those numbers should be about the same.  If it is way off, then your body’s scale is different from the replacement neck’s scale.

This entry was posted on Thursday, April 2nd, 2009 at 3:35 am and is filed under Guitar. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.