Bass Setup
Adjusting Bass Guitar Neck Relief
First, choose the gauge of bass strings you plan to use. Different string gauges have different amounts of tension. When you change gauges, you may have to readjust your bass guitar. So find a gauge you like and stick with it.
Make sure you've installed your strings correctly.
Tune your bass strings accurately to your preferred tuning. You want the string tension to be the same as when you play.
You'll want to get your bass neck as straight as possible before the point where the strings start buzzing. This will depend on how hard you play the strings. There's not one right answer.
Find the truss rod nut. Typically, it will be a hexagonal nut on one end of your bass neck. It may be covered by a plate on the headstock. Or, it may be hidden by your pickguard.
On some basses you may be required to remove the neck, adjust it, put it back on and then tune the strings up again. If it's not right, you'll have to do it all over again. (What a pain!)
It doesn't take much turning of the truss rod to adjust the neck. Never force anything! Expect to maybe do a quarter-turn or a half-turn.
Use the correct size hex key so you don't strip the truss rod nut. Your bass may have come with the hex key you need.
To avoid breaking the truss rod, first loosen it by turning it to the left (lefty-loosey).
Now, start tightening the truss rod by turning it to the right (righty-tighty). You may find the strings to be in the way of turning the truss rod. If they are, detune/loosen them and move them out of the way while you turn the truss rod. Tune the string(s) back to pitch to check the straightness of the neck.
You can check the straightness with a straight edge of some sort. Or, you can use your bass strings as a straight edge. Fret the 1st fret and the 15th fret of your lowest string. You should be able to see how much relief is in your neck by checking the space between the bottom of the string and the tops of the frets. You'll probably need just a tiny bit of relief.
Don't be surprised if it takes several days for your adjustments to settle in. You may have it perfect one day only to find it has moved the next day!
Pickup Height
The higher your bass pickups are set, the louder the output of your bass.
You want to adjust your pickup height so that the strings don't clack against them and that the output isn't too hot (loud). Also, the magnets may pull on your strings if the pickups get too close.
Don't set the pickups too low or else you won't get enough volume out of your bass.
The Straightness of the Bass Neck
The straightness of the bass guitar's neck is commonly called relief. The neck bends upwards (called up-bow), or it can be straight, or it can bend backwards (called back-bow).
Two things cause the neck to bend:
1. the tension of the strings pulling the neck upward
2. the truss rod pulling the neck backward
The truss rod is a metal rod inside the neck of your bass. The rod can be tightened or loosened. As it is tightened, it exerts more pressure on the neck forcing it to bend backward in the opposite direction of the string tension. When loosened, the truss rod relieves the pressure adding relief (up-bow).
Always be careful making truss rod adjustments. If you over-tighten it, you can make it snap and ruin your bass neck!
You can sight your neck by holding the body of your bass and looking from the bridge toward the nut. (See picture.) Sighting your neck will give you a quick idea of how much relief is in your neck.
Your neck needs at least a slight amount of relief so that the strings don't buzz against the frets.
Strings vibrate in an elliptical pattern. That is, they vibrate more widely in the center of their length. So, a little relief is needed for them to not hit the frets. If your neck is straight or back-bowed, the strings may rattle against the frets causing unpleasant fret buzz.
Setting Bass Intonation
To set the intonation of your bass guitar, you must lengthen or shorten the string by moving the string's saddle backward or forward. You do this by tightening or loosening the intonation screws at the back of the bridge.
How to Set Your Intonation:
Using an electronic tuner, tune all the open strings to their correct pitches.
Starting with your lowest string, fret the string at the 12th fret. Make sure you press the string straight down. You want this fretted note to be in tune. It should be the same note as the open string.
Check the electronic bass tuner to see if you are flat (too low) or sharp (too high).
If you are sharp, you need to add length to the string by moving the saddle backward.
After you adjust the saddle, double check the open string is still in tune.
Do the same for each string.
You will discover that it is impossible to get every single fret perfectly in tune. This is normal. Fretted instruments have a natural flaw where they can't be perfectly intonated. You can just get really close. If you're interested in why, look up "equal temperament" or "just intonation" in a music dictionary.
Intonation is how in-tune something is. That is, how accurately something hits the correct pitch. This can be said of singers, "Her intonation is spectacular. She nailed every note!" Or, of instruments, "I need to adjust my bass guitar's intonation. It plays so out of tune even the drummer can tell!"
Notes occur at exact points up and down the string. Setting your intonation means matching, or lining up, where the notes occur on the string to where the frets are on the fretboard. If they are not lined up correctly, your bass guitar will play out of tune.
As you will see in the setting bass intonation tutorial, to adjust your bass intonation you will move the saddle forward or backward.
By moving the saddle, you change the length of the string from the bridge to the nut. Changing the string's length shifts where the notes fall on the string.
Adjusting Bass Guitar String Height
Once you've adjusted your neck relief, you can raise or lower each string's height with their saddles.
Depending on your playing style, you may want the strings higher or lower. Experiment.
Adjust the height of your lowest string so you don't get any string buzz. Check the open string and all the frets up and down the neck for buzz.
A little string buzz is normal.
Use a radius gauge to identify the radius of your fretboard. If you don't want to remove your strings, cut notches out of the radius gauge where your strings fall. Then you can set it on the fretboard without removing the strings.
Once you know your fretboard radius, set the radius gauge on top of your saddles and adjust the heights of the other strings to match the fretboard radius.
You can also attempt to just eyeball the radius. Make it feel right and balanced.
