They enter my things ,Yeah your answer could be as easy as a nice outboard preamp. A pedal. But def try new strings first. It sounds to me like your ear is wanting to hear something that your gear isn't giving you.
How did you come about using the stuff you have now @wishforbass? Hand me downs? Bought after searching and researching? Bought on a recommendation? I would suggest this as well, go to a music store and try out everything they have available in the bass room. See if something speaks to you. Because it really does just sound like your staled on your gear to me. But I could be wrong. Maybe you just need an exciter or something like that....
Don't laugh as local bassist I'm alone ,in city there are less than 10 .
We buy things from shop then they enter our stuff for us .
Like I wanna a bass ,there is no good bass available .so I go store (they know us ),we search in a website like sweetwater .
Then they say their price for enter then we go other shop they say their price too and we choose which ship enter our stuff from Italia or USA mostly and Indonesia .
So there is no pedal available till I want it .
Bass room ,sorry we don't have even string so room is too much.
Expect normal guitar and electric guitar because have too much fan .