I like getting along with sound guys.
I play many of the same clubs, frequently, and having a solid working relationship with them is mutually beneficial in many ways.
When I was local, I worked with sound guys..national, had my own, and then at some points, to help bars start a live music venue I have been a soundguy.
If every player was like you, life would be gravy.
The worst way to go about things is to be high strung and antsy - especially as a local artist.
I see some bands come in that are nervous or irritable for whatever reason and they make demands..etc. It is the best way to get a bad rep real fast. Sound guys that are decent know everyone in town and word spreads fast.
There is no need to fear the soundguy or let him give you a bad tone either. The secret is to really know your stuff and clearly communicate with that guy so he knows you are cool and know what you are doing.
The facts are that the majority of bass players in local bands that I have heard have a crappy tone that usually consists of too many lows or too many highs. Many play too loud, have hissy equipment..etc.
Anywa, to overcome this bias, just be cool. Be relaxed..know your stuff and know how to communicate with people. If it is a 3 band or more show, there is a ton of stress coming from the sound guys angle and you need to acknowledge that and make things as smooth as possible. He may only have time for 1 line check so you better understand that and have a better option that will work on the first try.
If you can pull that off, you will get what you want. Trust me. I have been playing this game for years and the majority of being successful in music is simply being good with people.