The double-bass differs in several ways from the instruments of the violin family. In its modern form it is a hybrid, combining elements of both the viola da gamba and the violin families. From the gamba it retains the sloping shoulders, the generally relatively flat back and the string tunings to fourths (older instruments also retain the frets and the five to six strings). The F-shaped sound holes, the scroll, the often rounded back and the ribs with corners come from the violin. Inside the body a wide cross bar reinforces the sound post. Historically and in terms of its original construction the double-bass belongs to the gamba family, but the developments it underwent made it increasingly similar to the instruments of the violin family.



The ribs are very high in relation to the other stringed instruments, which is necessary to achieve the required resonance. They give the double-bass a rather box-like appearance, which has earned it the affectionate nickname “doghouse” among jazz musicians. The ribs become flatter toward the neck so they do not hinder access to the higher positions on the fingerboard.



For solo performance the strings are generally tuned a whole note higher to produce a brighter timbre (scordatura).



The bow is shorter and thicker than the cello bow. Horsehair is stretched between the two ends of the bow, with rosin ensuring it remains in contact with the string. Two types of bow are used: the French bow, which is similar to the cello bow but shorter and thicker. It is bowed overhand, the back of the hand facing the listener; and the German bow, slimmer, with thinner horsehair and a wider frog which is bowed underarm , the thumb facing upward.

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The playing position has more to do with personal taste than the size of the instrument: some soloists play standing while others prefer to sit on a long-legged stool. The question why one should prefer to stand and the other to sit is a philosophical one