Steve, without knowing exactly what bass (p-bass, upright, synth,etc), amp, how it ), was played (pick finger, felt pick,and effects the only option is to use your ears, i.e. exactly what you are trying to do.
Fender Jazz Bass mainly played with no pick with flatwounds
40W Fender Bronco:
Gain: 0
Bass: 3 O'clock
Mid: 9 O'clock
Treble: 9 O'clock
Master: 12 O'clock
Model Pre-set: Rumble
Comp: Off
FX: Off . . . Like I say, this is a big subject.
But doesn't any post-processing of the waveform in a DAW basically step on the above settings anyway?
As for purchasing additional Plug-ins, I already have a boatload of Plug-ins that come bundled with S1. Ampire is one that and hasn't given me anything close to what I'm seeking. Plus don't these plug-ins basically package-up a combination of frequency, gain and Q adjustments into a friendly user interface? Pro-EQ does that for me, plus I can make micro adjustments if needed. Or do you think there is there more going on under the hood in these Plug-ins that is relevant to the tone I'm seeking?
As it happens I do have a few bass synths on the Korg keyboard that actually sound deep and fat thru the JBLs. But I enjoy my Jazz Bass too much to even consider playing bass on a keyboard.
And yes, I have no interest in Plug-ins designed for 6-string guitar.