Editing Eight-string guitar (section)

===Scale length===
The main design issue faced with an eight-string guitar is tuning stability with the lower strings. This is due to the neck being constructed too short, bridge problems such as improper intonation, uneven spacing for floating bridges, or the use of wrong string gauges. Other problems associated with tuning stability rely on the proper setup of the guitar.

Extended range eight string guitars sometimes will have a [[multi-scale fingerboard|multi-scale]] design where the bass strings will be longer than the treble strings (fanned fret design). This helps with proper [[Intonation (music)#Fretted instrument intonation|intonation]] of the lower strings, improves string tension balance across the strings, improves [[Guitar harmonic#Overtones|harmonic overtones]], [[overtone series]], and improves [[inharmonicity]]. (See also [[Piano acoustics#Inharmonicity and piano size|inharmonicity in pianos]]). The bass strings on an 8 string typically require the saddle to be pulled back a bit more than the other strings to properly set the intonation. Some bridge designs accommodate this by offsetting back the 7th and 8th strings or providing a bit extra room for adjustment. Longer scale lengths require less offset for proper intonation. {{fact|date=May 2017}}