There are many factors to the sound - strings, body and neck woods (poly and nitro finishes), pickups (active, ceramic, alnico) all affect the tone. This is all before even going to an amp and cab.
Generally the strings have the biggest impact on one's sound, then pickups, then woods (Inc finish). Don't always dismiss what might be referred to as cheaper wood bodies, like basswood. Some basses no matter what they are made of, or how they are finished just sound better than others.