I couldn't possibly comment on the sound guy part, though he probably will have a bit of an influence.
I found that depending on the band I was in I would have to change my amp eq and bass eq.
When I was in a Thrash metal band with two guitarists, my bass was set to sound quite horrible when played on its own. Harsh and snappy with a bit of low end too. But when played with my guitarist, who is very much in love with his treble, and the other guitarist, who seemed to take more of the sonic space up, the bass cut through as best it could.
Other rocky / blues bands I was in I could afford a bit more of a smoother rounder tone, to add some fatness and warmth to the nice mellow guitars. If my bass was still set to this in the thrash band, the whole thing would have sounded a mess. And like wise the other way around too, but it would have cut through still but would have ruined the sound.
I haven't had too much experience in the FOH sound section. And I never really know how it sounds from the audience's point of view. This being due to poor FOH (edit: poor stages/ set ups, not the sound guys fault half the time). and lack of monitors etc...
I like to be heard / hear myself a lot when I play live, but never for the wrong reasons.