Action refers to the distance between the frets and the string.
To measure the action, tune the guitar accurately; then place a ruler at the 14th fret and measure the distance from the top of the fret to the bottom of the string.
and 2.0 mm--2.2 mm for the sixth string.
For a seven-string guitar, the seventh string should be at 2.2 mm--2.4 mm. For eight-string and nine string guitar, the eight string should be at 2.4mm--2.6mm.
For bass, there should be about 2.0 mm at the 12th fret for the high strings and about 2.5 mm for the low strings for typical playability. For strings other than those listed above, adjust the action so that the distance gradually increases from string buzz, muted notes, or poor sustain. If you experience string buzz or muted notes even when the action is adjusted correctly, you might need to adjust the neck bow.
※ The method of adjusting the action will depend on the type of tremolo/bridge with which your guitar is equipped. For details, refer to the appropriate tremolo/bridge section. ※
For the bridges with stud lock function, make sure that the stud locks are released before you adjust the heigh