Relief

For any guitar to play with a low, buzz-free action, a slight amount of concave forward bow is necessary in the neck because of the elliptical shape of each string’s vibration. This concave bow is called “relief.” Neck relief is generally measured at the 7th or 8th fret. If you have never adjusted a guitar neck’s truss rod, it’s best to leave that to professionals, particularly as it is not expensive to have done (some will do it for free to assure your future business). However, a botched “do-it-yourself” adjustment can cause serious damage to your instrument.