Relief, or profile, refers to the amount of curvature in the fingerboard of a guitar or other similar stringed instrument.
When the strings of a guitar vibrate, they vibrate in an elliptical shape. Thus, providing the best possible
action
Action may refer to:
* Action (narrative), a literary mode
* Action fiction, a type of genre fiction
* Action game, a genre of video game
Film
* Action film, a genre of film
* ''Action'' (1921 film), a film by John Ford
* ''Action'' (1980 fil ...
requires that the guitar fingerboard have a slight curve to allow the strings to vibrate freely. Incorrect relief may cause
fret buzz
A fret is any of the thin strips of material, usually metal wire, inserted laterally at specific positions along the neck or fretboard of a stringed instrument. Frets usually extend across the full width of the neck. On some historical instrume ...
.
To provide adjustable relief, most guitars have an adjustable
truss rod
The truss rod is a component of a guitar or other stringed instrument that stabilizes the lengthwise forward curvature (also called ''relief'') of the neck. Usually, it is a steel bar or rod that runs through the inside of the neck, beneath the fi ...
. Some guitars, such as certain older Guild 12-strings, have two parallel truss rods. Turning the truss rod screw changes the tension of the truss rod, and thus the relief. Novice players should not attempt this, as the
guitar neck
The neck is the part of certain string instruments that projects from the main body and is the base of the fingerboard, where the fingers are placed to stop the strings at different pitches. Guitars, banjos, ukuleles, lutes, the violin family, and ...
can easily be damaged or broken.
As the wood of the guitar neck is affected by temperature and humidity (weather and climate), relief may change with these altering conditions. Compensation for this may be required if fret buzz occurs, by adjusting the truss rod.
References
String instrument construction
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