When I was still working for Jan Knooren custom basses, Jan himself used to tell about John Pattitucci with whom he had a friendship.
That friendship came about when the two of them met when Jan still lived in LA. Pattitucci back then played THESE.
Ken Smith 6 string basses, which as I was told was a compromise, since he never liked the way those basses sounded. It came down to the way those basses were constructed, because those multilayered "Hippie Sandwich" bodies and through neck construction killed off any natural acoustics the instrument had.
John using his Ken Smith in 1986.
So Jan proposed to build him a custom six string which would rectify that issue, using two pieces of figured walnut and a one piece maple neck.
Not the actual bass but a similar style.
And a few years later, Pattitucci began endorsing Yamaha and their TRB bass. Which goes even more the Fender route by having an ash body and a bolt on neck.
So it's more than just the EQ on a bass which makes it sound the way it sounds.