3. adjusting string height (Action) at the 12th fret
Your expensive guitar is sort of worthless if it’s annoying to play. There is a range of ideal height for your guitar strings depending on your playing style. The guitar’s action is a term that’s used to describe its playability. Saying a guitar has great action is a very subjective statement. Someone who plays lead acoustic in a bluegrass band needs an action that is very different from the needs of a person who plays jazz, chord melody, blues style, or other fingerpicking styles. My focus will be on setup for nylon stringed guitars, whether used for classical, jazz, singer songwriter, etc.
The guitar’s action is measured using, among other things, the strings’ height at the 12th fret. There’s also a 13th fret school of thought which involves putting a capo on the 1st fret and checking the strings’ height at the 13th fret. Whichever you choose, the string’s height is: the distance between the top of the fret and the bottom of the string. You’ll need a precision measuring tool to check the height of the strings at the 12th fret. Get yourself one of these:
- To become acquainted with using it, place the measuring tool on top of the fret. Look at the bottom of the string and see where it aligns with a mark on the measuring tool. Take several looks as it may be an adjustment from using imperial units (inches) or you may not be used to looking at such tiny increments. A one hundredth of an inch in this case is a big deal in either direction so using millimeters is far easier.
- Look at the chart below. These are my ideal string heights (in mm) for nylon strings. I have arrived at these numbers by using an average of many different (and respected) sources.