I’ve been using passive basses exclusively for quite some time now. However, having tried out a few Sadowskys, I added one of their preamp pedals to my board, it just adds the right magic to lift the sound, without colouring it, which isn’t available in the amp’s eq. It is just 2 band and boost only, but I find that there’s already enough mid range in my basses, so I just need tweaks in the other ranges to achieve what I’m after. YMMV.