On the one hand, every single tiny component of a bass is involved in its vibration in some small way, so
technically even the pickguard screws have
something to do with the sound.

However the point where there's an actually
audible difference is hotly debated. Some would argue that even the bridge and nut don't make that much difference. Roger Sadowsky said something to the effect of the body wood making only a negligible difference to the tone, whereas he thought the fingerboard wood made a really audible difference. It's all over the map, and there is a mix of truth, hokum, and subjective experience all stirred together.
Getting a punchy, trebley Ric tone: use brand-new bright stainless roundwounds. Set it up with low action so you get a bit of fret buzz. Play with a pick. Emphasize the bridge pickup. That should get you there!