The way to get a good bass tone that works for me every time with an amp with a 3 band eq and a good amount of power, cabinets that aren't blown and can represent some idea of bottom end...
Starting blocks:
EQ
Bass 0
Mids 10
Treble 0
Master * 10, or with desired gain structure interacting with the....
Volume * setting it to where you can comfortably hear yourself, tone will likely be ugly (and Mid forward) with this EQ, and that's ok.
Add treble to taste. I do this by dead snapping the G string, to just get that Twack against the frets (something that generates the most amount of treble that will come from the instrument). Adjusting the treble should swing from Muffled, to Warm, to Open, to Piercing. I do this with the tone on the bass wide open (or on an active bass set flat) This way even without the support of any bottom end on the amp I'll never have something piercing or harsh in the top end. This is totally supjective.
Add Bass to taste. Here I palm mute the lowest string and dead thump it with my thumb to generate the most low end from the instrument. Dialing in here goes from a lean, to Full, to Fat, to Reggae, to Bill Laswell. Here it's important to keep in mind how that low end is interacting with the room, what's right in one room will not be right in another. And listening from it going from anemic to fuller will give you an idea of that interaction and how much your amp will give you in that regard.
Dial back Mids to taste. The tone you are left with after going through the initial setup will be very mid forward, and seemingly loud because of it to adjusting the mids down here may also affect your overall volume try not to compensate because of this logic.
At this point you have added ALL the treble you would ever add with out the support of the bottom end in relation to ALL the mids your amp can put out. Then in relation to all that, you have added all the bass that either the Room, the cabinet, or your amp can represent. If there is anything 'wrong' with your tone the only control that needs to be changed is the mids. The less you change the mids the better.
On a passive bass, I'll generally roll the tone back a bit, but as the night rolls on open or close it up as need be. On an active bass I'll roll the treble back from flat, and boost the bass a bit just to hit the amp with a bit of bottom.