Al Kraft makes an excellent point above. If you have any friends that are bass players - especially with a good ear - try to spot them in the audience for feed back on the sound. Take a small personal notebook and make notes on the amp and EQ settings that seem to work the best from out front.
Sometimes, I have had a friend sit in on one song so I could hear the bass from out front and refine the EQ so that sits better in the mix. It is guaranteed not to be the optimum "bedroom mix".
Another good thing to do is to get the set or performance recorded. You sometimes think you had a killer night, but then you sit down and listen to yourself and every little detail that you screwed up jumps out at you. Like: leading in too early, hesitating, dropping a string, missed changes, poor attack, lagging, lines that didn't approach well, (your drummer's attempt to make the ONE and a half turn into the new ONE), excessive finger clank, poor timing in changing pickup selections or EQ, and pretty much everything else that can humanly go wrong. Rather than get frustrated over this, it is a great tool to illuminate what you did wrong so you can fix it, and it also can illuminate the times the lines worked well and you were in the zone and locked into "Can't do no wrong and can't hit a bad note" land.
By doing this, you eliminate the bad, refine the good and get your parts simplified, effective, locked up and repeatable with good solid groove. Well worth the psychological pain and effort.