dude said:
Warping involves contraction of the wood to the point where playability drops beyond normal means. If you see down the line of your neck you'll realise that your neck most probably has a slight curve to it, mine. How much curvature you want on your fingerboard depends on how you adjust your truss rod.
The truss rod is a metal rod in your neck that stablizes your neck and counters the tension that your string creates when you tune your bass up.
So here's one simple way to check the curvature of your neck. Sit down with your bass and fret the first fret of any string, i would recommend you start with the low E, if you play a 5-string, then the low B. Afterward, use your elbow to press down the strings at the end of the neck very near to the neck pickup. Make sure the strings are touching the frets. What you've done is to create a perfectly straight line in comparision with your neck. You'll notice that there should be some kind of space in-between your strings and the surface of your fingerboard, if there isn't, most probably your neck is too straight.
If there's a space, follow the next step, use your finger to press down in the middle of the contact point of your fretting finger and your elbow, simply, just the middle of the string lah. This measures how much relief your neck has. Mine has a relief the thickness of a credit card. I would recommend that you give your neck a little curve to allow the strings to "breathe". If you are a hard player, that means you strike really hard on the strings, maybe you would like to raise your string height to accomodate the vibration of your strings, to prevent alot of string buzz.
Or if you want, you can actually get thicker gauge strings. This will help in reduced the vibrations of the strings and allows you to lower your action a little so that your action can be lower.
Cheers! Hope this helps.