This instrument was created so that you could add an even lower and more voluminous sound to the orchestra than the double bass. The sounds that can be extracted with the help of octobass strings are the lowest sounds that a person can in principle hear (16 Hz – 20 kHz). The lower frequencies are simply not detected by the human ear.
Since the instrument is so monumental (the largest specimens reached 4.5 meters in height and almost 2 meters wide!), The technique of playing it is special. First, the musician stands on a special stand to reach for the strings and fretboard. Secondly, the thickness of the strings does not allow you to clamp them with your fingers, so the octobass has special levers for each string on each fret, so they can be pressed by hand or foot, respectively, the musician stands on one leg. The musician leads the strings with a bow.
But the hopes of the inventors did not come true: the octobass turned out to be very cumbersome, it is quite difficult to play on it, and the instrument still does not give the right amount of sound. Therefore, the subcontrabass has not become widespread, although some music groups use it today for their performances as exotics.
Modern double basses cannot completely replace octobass, but on some models the manufacturers add an additional fifth string, the sound of which allows you to take very low notes. And in some models special devices are mounted, allowing to “underestimate” the sound of the string due to its virtual lengthening.