Step 3: Inspect the Nut Slots
Next, we check the nut slots and the string height at this end of the neck.
1. Tune up.
2. Hold each string down on the 2nd fret and look at the space between the bottom of the string and the top of the 1st fret (Photo 9). We want this clearance to be as small as possible, yet when you play the open string, you don’t want to hear it buzz against the 1st fret. If the clearance is insufficient, you’ll get a buzz.
9. Checking action at the 1st fret while holding the string against the 2nd fret. In addition to eyeballing the clearance, tap the string against the fret to determine the distance between them. 10. Deepening the 2nd-string nut slot.
For bass guitar, a good middle-of-the-road clearance over the 1st fret (with the string still pressed against the 2nd fret) would be the thickness of one business card. If the string has more than that amount of space, the respective nut slot may need to be deepened (Photo 10) so the action at the 1st and 2nd frets is low enough to play comfortably and you don’t pull the strings sharp trying to press them against the frets.
Anyone can get nut files from Stewart-MacDonald (stewmac.com) or Luthiers Mercantile (lmii.com), but there is more to cutting a proper nut slot than just making a groove. It needs to be exactly the proper size for each string. The slot must hold a string firmly in place so it can’t move around or sympathetically vibrate against the sides of the nut slot, but not be so tight that the string binds and hangs in the slot and then goes out of tune when it’s stretched or played.
Also, the slot needs to be gently angled downward as it points back toward the headstock (Photo 11). The string must “speak” from the nut’s front edge—right where the nut touches the fretboard and not somewhere inside the nut slot. (If a string rests on a point inside the slot, rather than at the leading edge, this can create a “sitar” effect or cause a string to play out-oftune along the fretboard.)
11. A slot needs to be gently angled downward as it points back toward the headstock and the string must “speak” from the nut’s front edge—right where the nut touches the fretboard. 12. When deepening a nut slot, recheck the 1st-fret action after a few light strokes with the file.
If you deepen a nut slot, work very slowly and frequently recheck the action at the 1st fret after a stroke or two of the nut file (Photo 12).
If a string touches the 1st fret when you press it against the 2nd fret, then the nut slot is too low. The offending slot will have to be filled and then fine-tuned with a nut file, or the nut itself shimmed to gain more height, or you need to fabricate a new nut. Sonically and mechanically, the latter is the best option. If you’re not comfortable tackling this project, see your repair tech. [For detailed explanations on cutting a bone nut, visit premierguitar. com and read “How to Convert Your Axe to a Baritone,” “How to Intonate a Flattop Guitar,” and “How to Convert a Flattop to Nashville Tuning” in the March, April, and September 2012 issues.]
Step 4: Adjust Saddle Height
Now we’re ready to check and adjust string height at the bridge.
13. Measuring the distance between the 4th string and 12th fret with a precision metal ruler. 14. Measuring the distance between the 1st string and 12th fret.
1. Tune up. (This is automatic by now, right?)
2. At the 12th fret, measure the distance between the bottom of each string and the top of the fret (Photos 13 and 14).
3. Using the appropriate wrench, adjust each saddle up or down to the desired height (Photos 15 and 16).
Naturally, string action has to be adjusted for an individual’s playing style. If you have a light touch and play very technically, you can get away with slightly lower action. However, you’ll want a somewhat higher action if you love to dig into the strings and produce big, clear, sustaining tones. By experimenting, you’ll eventually determine the ideal action for your music—and that’s the beauty of learning how to do a setup yourself.
For a middle-of-theroad action, I set the bass side of a 4-string (the E string in standard tuning) to 7/64", and then set the treble side (G string) to 5/64". I then graduate the heights as I go across the fretboard, making it 6+/64" on the A string and 6-/64" on the D string.
The goal is to gradually make the strings go from higher to lower as they cross the fretboard from the bass to treble side. With multi-string basses (5, 6, and more), continue this concept across the strings by adding some height for lower strings and shaving a little off for higher ones.
15. Adjusting saddle height for the 1st string.16. Another view of saddle-height adjustment. Here, the 2nd string is being raised.
17. Once the neck relief, nut slots, and basic saddle height have all been adjusted, it’s a good time to check fret condition.
Evaluate Your Frets
Once you have the strings close to their proper height with the instrument at pitch and the previous adjustments dialed in, you can really see if the frets are level all the way along the fretboard. We’re now at the stage in the setup where fret problems will be revealed (Photo 17).
High or low frets, loose frets, and even dead spots from the buildup of gunk and funk that gradually seeps between the frets and fretboard over the years can create inconsistent string vibration, so be on the lookout for these problems.
Speaking of fret condition, if you notice that even after being tuned to pitch and intonated (which we will get to in a moment), your bass does not play in tune with itself on some notes, check to see whether your frets have a nice round crown on top or if they’re flat. Frets that are worn flat will allow the string to read from either the front edge of the fret and play sharp, or read from the back side of the fret and create a sitar-like sound. Having your frets in level, crowned, tip-top condition is essential for optimal playability, focused sound, and spot-on intonation. Fretwork is definitely the domain of a trusted repair technician.
Step 6: Adjust Intonation
Now we’re ready to check and adjust intonation. Unless the strings are fresh, install a new set before going any further.
Intonating your instrument involves individually adjusting the length of each string so its notes are in tune along the entire fretboard. To do this, it’s best to use a strobe tuner (Photo 18) because it lets you visually track incremental pitch changes in both a note’s fundamental vibration and its overtones.
18. A strobe tuner or pedal with strobe functions provides superior visual feedback for setting intonation. 19. Properly wound strings wrap from the top of the post to its bottom. The wraps should lie tight against one another and not overlap.
Before we start, here are some tuning tips to consider. In my experience, you’ll end up with a more stable tuning if you come up to pitch from below. By tuning up, you reduce the possibility of slack being in the string that could release while you’re playing.
Also, be sure the windings progress around the post sequentially from top to bottom—with no overlapping—and that these winds are snug or butted up against each other so they can’t move around (Photo 19).
Stretching is important too. I spend time stretching strings when they’re new. Usually tuning up to pitch and stretching a string six to eight times will get it stable. There’s no need to really yank— applying a firm upward pull as you move along the string’s entire playing length is sufficient.
1. After your strings are properly installed, stretched, and all tuned to pitch, start with the lowest string and make sure it’s in tune while you play it open. Then, on the same string, play the note at the 12th fret. The open string is your reference, and the 12th-fret note—which is an octave higher—should also be in tune without you touching the string’s tuning machine. If the 12th-fret tone isn’t in tune, you’ll make adjustments at the saddle to raise or lower the fretted note’s pitch until that note is in tune with the open string.
With that in mind, also take care to play the 12th-fret note as if you were performing it—not with less or more pressure than you’d use to play the note while you’re onstage.
2. If the high octave—the fretted note—is sharper than the open pitch, this means the speaking length of your string is too short. That is, the distance between the fretted octave and the saddle is too small. If that’s the case, you need to make the string slightly longer by moving the saddle away from the neck.
Conversely, if the fretted octave is flatter than the open string, the vibrating section of the string between the 12th fret and saddle is too long and needs to be shortened a tad. To do this, move the saddle toward the neck.
Different basses have different processes for shifting the saddle backward or forward (Photo 20). This can include loosening setscrews to allow the saddles to have forward and backward motion. If you’re not sure how your saddles operate, consult the owner‘s manual that came with your bass or go online to research the particular bridge.
3. After the bottom string is intonated, move to the 3rd string, then the 2nd, and finally the 1st.
20. Using a Phillips screwdriver to shift the 2nd-string saddle backward. 21. Checking the low-E’s second-octave fifth interval—that’s B at the 19th fret—with a tuner to see how it’s intonating after the octave has been adjusted.
Tip: Make small adjustments and always retune before making another adjustment. Be patient— it’s a painstaking process, but well worth the time investment.
Once I get the 12-fret octaves in tune with their respective open strings, I like to check if the fifth of each open string is in tune. For example, assuming my 4th string is tuned to E— standard tuning—the fifth is B, which occurs at the 7th fret and also one octave higher at the 19th fret (Photo 21).
There are articles and books that explain the math behind the 12-tone, equal-tempered tuning system that Western instruments—including the bass guitar—are designed around. It’s beyond the scope of this DIY tutorial to delve into the details of equal temperament, but in a nutshell, the system presumes that your octaves are perfectly in tune. All other intervals are fudged by a few cents from their pure harmonic form to allow the octave to be evenly divided into 12 notes, or half-steps. (Each half-step consists of 100 cents.)
In practical terms, once you’ve intonated each string so the octave is in tune with its corresponding open string, you may find that the fifth—a crucial note for bassists—is disagreeably out of tune. This can be a result of equal-temperament “fudging” and how it affects fret placement, but also the thickness and material of a given string can contribute to the issue. We are, after all, simply stretching wire into different vibrating lengths to make music—a primitive scheme when you think about it.
If it happens, let’s say, that the 19th-fret B on the 4th string is a little sharp, but the octave is dead on, I may fudge the intonation a little bit to favor the B note. This entails moving the saddle back slightly to reduce the sharpness of the B. It’s a tricky and imperfect game—you don’t want to put your octave noticeably out of tune because then the whole equal-tempered tuning system collapses.
If you find large discrepancies between the correctly tuned open string and its octave relative to other intervals, seek out an experienced repair technician who can help you diagnose and remedy such intonation troubles. There are a lot of techniques available to address this particular dilemma.
Step 7: Check Electronics
As a part of my setups, I also include a thorough electronics check. Dirty pots, loose pots or jacks, and loose knobs can all interrupt the seamless connection between performer and instrument. Often the scratchy sound from a dirty pot can be remedied with a squirt of contact cleaner. This requires disassembly, and depending on your instrument, you may want to have your tech handle it.
As you troubleshoot and adjust your instrument, remember that the aim is to remove everything that can distract or hinder you from playing music. Between you and an experienced repair technician, you should be able to achieve this goal. Good luck!