Open tune your instrument (ie. don’t fret anything) to the tuning you’re planning to play in. Tune all of the strings directly to the tuner. No 5th fret or harmonic tuning here. For electric or acoustic-electric instruments: Use an electric tuner that you can plug directly into. For acoustic instruments: Use an extremely quiet (and dead) room with a mic tuner. Remember, set up your instrument for the tuning you’re going to use. If your band plays in drop D, Ab standard, G modal, or any other tuning you should tune your instrument to the tuning you are going to use. Bassists: Throughout this process you should be using a pick, even if you do not normally play with one. The way we pluck the string with our fingers works very well when we’re playing, but it just is not accurate (or consistent) enough for this process. For all instruments: Tune the entire instrument several times. As the tension on each string changes it may alter the way your neck is sitting and, thusly, may detune your other strings. Don’t move on from here until every string is open tuned as close as possible to perfect. When you’re tuned, move on to the next step.

2. Adjust The Action (Optional)

If you have any desire to raise or lower your string action (the distance between your strings and the fretboard) you should do it now. If you alter your action after you complete the intonation setting process, you may undo all of the work you are about to do. If you do alter your action on any string, repeat step

3. How Far Off Are You?

Fret the string at the 12h fret and pick it. The pick should be moderate, not too hard, not too soft. When fretting, pay special attention to fret only as hard as is necessary to prevent the string from buzzing. Even with a standard un-scalloped fretboard it is possible (especially on guitar) to bend the string sharp several cents by fretting too hard. In normal playing it isn’t generally an issue, but for this process you need maximum accuracy. When you play that string at the 12th fret, observe your tuner. If you are sharp (too high) or flat (too low) your intonations are off and an adjustment will need to be made.

4. Fix It

If (when playing the string at the 12th fret) you are sharp (too high) then the bridge is too close to the center of the string, and you need to make the vibrating length of the string longer. Fix: Move the bridge away from the fretboard (by rotating the screwdriver away from you). FLAT: If (when playing the string at the 12th fret) you are flat (too low) then the bridge is too far from the center of the string, and you need to make the vibrating length of the string shorter. Fix: Move the bridge toward the fretboard (by rotating the screwdriver towards you).

5. Check It

After you make a bridge adjustment, you will need to repeat step 2. Make sure the ENTIRE instrument is still perfectly in tune. Once you have completed step 1 again, re-fret the 12th fret on the string you just made the adjustment on and check it on the tuner. You should see that it is not in the same place anymore. If the 12th fret note isn’t perfectly in tune while the open note is perfectly in tune, you need to repeat step 4 until it is. If it is perfect you are done with that string.

6. Do The Rest

Repeat the process as outlined here for each string on the instrument tuning frequently.