Setup for Great Action
Step 3: Neck Bow - Truss Rod adjustment
Buzzing above the 10-12th fret is likely due to the bridge being too low. Buzzing from frets 2-7 is usually from truss rod maladjustment - the neck does not have enough bow. Likewise poor action can be enhanced by increased neck bow. If your neck is well warn have a tech examine it for defects or problems that may need to be corrected in addition to the truss rod adjustment. Ken points out that buzzing above frets 10-12 can in some instanced be caused by "fretboard tongue warpage, low or high frets, or frets coming out of the slot." These are major repair items that a tech would need to tackle.
I honestly don't go crazy with exact trussrod measurements/adjustments because the neck bow on all guitars can change slightly with the seasons. What I do is make sure I have enough neck bow to eliminate buzzing from fret 2-7. Of the reference measurement, I set my guitars up for the maximum bow tolerance. A guitar string, when depressed at fret 1 & 24, is a quick and accurate straight edge. Use the string as a straight edge to visualize and measure neck bow. When the string is used as a straight edge you should see a subtle space between the bottom of the string and top of fret 7.
Step By Step: Neck Bow - Truss Rod Adjustment
- Small Phillips-head screwdriver - for trussrod cover
- Supplied Ibanez tool - for truss rod nut (7mm thin wall socket)
- Remove the trussrod cover by unscrewing the three cover screws.
- Hold the low-E string on fret 1 and 24. (You can use a capo, extra set of hands, rubber bands, etc..)
- Now check the measurement at Fret 7
- Adjust the neck "relief" - make one small change (1/4 to 1/3 turn) at a time
- More neck bow needed (not enough clearance) - loosen trussrod
- Less neck bow needed (too much clearance) - tighten trussrod
- Retune the guitar
- Let the guitar settle for 15-60 minutes while playing or hanging/standing
- Recheck the measurement and repeat as necessary
- When finished, reinstall the truss rod cover
- 0.178 to 0.432 mm (0.007 - 0.017 inches) at fret 7
Summary - Step 3
Proper neck bow adjustment is critical for good action with no buzzing. Too little neck bow will cause buzzing on frets 2-7, whereas too much neck bow will cause higher than necessary action at the lower frets. Neck bow requires time for the neck to settle, so make a change, retune then recheck the measurements again after several minutes.