Have fun and sorry for any engineers who've been assholes about your volume (or in general). I meet too many jaded knowitall shitty bar / club guys who don't put effort into a mix if they don't feel like it that night and it's frustrsting as an 'educated' consumer. Especially so when I can tell the band is giving it their all and rocking out. I have found that a lot of guys / gals in this industry have crusty cigarette and booze coated outsides with a soft gooey boozey interior and if you talk over the basics of what you want and treat them with respect (key word) they will work much harder. Don't call them a 'sound guy' or give too many specifics, but give an overall feel "We like plate reverbs on our vocals, we want the vocal about level with the snare in the mix, we like a kick drum with lots click and a little less woofiness if that's possible" understand the lingo and the limitations and your band will look good and sound good all over. This is also just my general opinion and advice, don't take it for end all be all, I am holier than thou, just what I've experienced that seems to make people the happiest.