The acoustic bass guitar is a bass instrument with a hollow wooden body similar to, though usually larger than a steel-string acoustic guitar. Like the traditional electric bass guitar and the double bass, the acoustic bass guitar commonly has four strings, which are normally tuned E-A-D-G, an octave below the lowest four strings of the 6-string guitar, which is the same tuning pitch as an electric bass guitar.
The acoustic bass guitar (sometimes shortened to acoustic bass or initialized ABG) is a bass instrument with a hollow wooden body similar to, though usually larger than a steel-string acoustic guitar.
There are also semi-acoustic models, fitted with pickups, for use with an amplifier. The soundbox of these instruments is not large enough to amplify the sound. Instead, it produces a distinctive tone when amplified, similarly to semi-acoustic electric guitars. Thin-body semi-acoustic basses such as the violin-shaped Höfner made famous by the early Beatles and several Fender models are not normally regarded as acoustic basses at all, but rather as hollow-bodied bass guitars.
There are also semi-acoustic basses such as Godin Guitars’ “A-Series” that, once amplified, sound much closer between acoustic bass guitars and upright basses (double bass), and have been used in professional circles to “simulate” one when it would be impractical for transportation and other reasons to use a full-sized upright bass.
As with semi-acoustic electric guitars, the line between acoustic instruments fitted with pickups and electric instruments with tone-enhancing bodies is sometimes hard to draw, especially when some instruments can also be equipped with a variety of pickups such as piezo pickups, the “standard” of acoustic-electric instruments as well as synth pickups that can replay “virtual” upright bass sounds and bring a semi-acoustic bass much closer to a double bass sonically.