Remember my almost endless list, have owned around 200 basses and still have 11. They all sound different of course, but not when I play them. It's a hard to admit fact : you'll always have the same sound whatever bass you will play and I'm not speaking of tweaking the amp sound, I'm speaking of what gets out the bass when you play. That's why you are human and not a robot. Make a simple experiment with a fellow bassist, play a bass at a precise position where both of you hear (quite) the same sound and then let your pal do the same : there will be a huge difference because you have both your inner sound that you'll always tend to hear, which is affected by endless factors including your technique, of course, and even weirder ones like education and what you eat...