On a tangent, my drummer complains often that he can't hear his kick, and we're not THAT loud in the studio. We've been running his kick through the PA, but I'm not sure how that's gonna jive with vocals when we gig.
Do you have a monitor for the drummer with its own mix ? Most bigger PAs have a special monitor speaker for the drummer that is similar to side fill monitors because they need to be able to have bass and kick in them. Bass and kick are usually not very loud in the front wedges so they are smaller.