If you know how to raise and lower the bridge on a bass guitar, you can make slight adjustments to the action of your bass. The saddles on the bridge can be lowered or raised by turning the screws at the top with an Allen wrench. When you adjust the saddles, you lower and raise the string height (the action).
Have a professional set up your bass the first time. After you get your bass back, take note of how high he or she set the saddles and how the strings feel. From then on, you can fine-tune your bass by comparing it to the original setup.
You can also use the saddles to adjust the intonation of your bass. If your bass goes out of tune when you play on the very high or very low frets, you need to adjust the intonation. To do this, find a screwdriver that fits into the screws at the back of the bridge. Turning these screws moves the saddles back and forth.
Play the harmonic of one of the strings at the 12th fret, and tune the string to the tuner.
When the harmonic of the string is in perfect tune, play the same string by fretting it at the 12th fret and compare the pitch of the note with the pitch of the harmonic.
If the fretted note is sharp compared to the harmonic, lengthen the string by tightening the screw.
This moves the saddle away from the neck. Now tune the string again using the harmonic. Keep adjusting the saddle until both the harmonic and the fretted note are in tune.
Adjusting the intonation.If the fretted note is flat, shorten the string by loosening the screw to move the saddle toward the neck.
Tune the string using the harmonic, and keep adjusting the saddle until both the harmonic and fretted note are in tune.
Repeat this process with all the strings.
Be patient when you’re adjusting your bass. It needs to be done only about four times a year (as the seasons change), but you have to take a whole afternoon to do it right, especially if you’re adjusting your bass for the first time. The process will bring you closer to your instrument — you know, bass bonding.