The headstock is NOT the culprit. If you know what they are, you should know what causes them. Deadspots are caused by sympathetic resonance that cancels out the string vibration, making it sound dead. EVERY bass/guitar will have them. It's just a matter of finding them. As I said before, it's possible that the location of the dead spot is off the fingerboard, but it does exist. Changing the headstock angle will do nothing to fix them, nor will adding mass. All it does is shift the spot around.I know exactly what it is. I'm intimately familiar with them. I have three basses (out of seven) which absolutely do not have them. Of those one is headless, one is carbon 35" and one is a wooden five string. All of my Fender style basses have them including one which is carbon. Seems to point at the Fender style headstock as a culprit. Fix it.