Originally Posted by XUSMC1775x
thank you for your answer, the saddles are fine. its difficult for me to adjust it when i loosen the strings, is there a specific way to do it without the strings loosened?
It's difficult for EVERYONE to adjust the truss rod when the strings are on and tuned! You just have to try to do the best you can. People who build basses never seem to think about adjusting it later! At worst, you can just loosen a couple center strings where the truss rod access is located if nothing else works.
The truss rod sets the BOW in the neck. You test the bow by fretting a center string at both the first fret and last fret and looking at the gap under THAT string at the center of the neck. That bow should never be more than the thickness of a couple of credit cards (and that is a BIG gap for people with high action) Usual is more like one card thickness.
The reason you adjust the neck with strings on and tuned is that if you take all tension off the neck, when you put it back on after an adjustment it takes a while (can be days) for the neck to settle back in. This can make a truss rod adjustment REALLY take a while. Even with tension on the neck there will be a certain stabilizing time. This where the 1/8 turn and wait rule comes from.
One you get the bow in the neck correct, THEN you use the saddles to set the string height at the highest frets. That's it. Really pretty simple except for the hassle of trying to adjust the truss rod with strings on and under tension.