I am fairly new to the bass world and yesterday I had my first jam session as a bass player with a couple of friends. there where 2 guitars, drums and bass but my problem was that as soon as everyone else started playing, the bass was almost inaudible and they kept telling me to raise the volume but I know that it is not a good idea to just turn the volume up to be heard in a rehearsal room. I just want some tips to better EQ the amp so that the bass sounds better in the mix. the bass amp is a GK 400rb