DOUBLE BASS STRING SET D'Addario J610 1/4 Prelude series Strings for Double Bass. Prelude Double Bass Strings have a braided steel multi-core that produces warm sound quality with good bow response. The special core design and tension reduction make these strings easy to play, especially for younger developing performers. Ideal for use in educational settings, the Prelude Bass Strings maintain a clear, warm sound that blends well into the ensemble. 1/4 scale strings specifically calibrated for 1/4 size double basses with a playable length of 35 1/2 inches (900mm).