I decided to tape record my band's last practice so we can see how we've improved as time goes on. The music picked up really well, but the vocals were almost impossible to hear. If I remember correctly, we just plugged the mic into an extra guitar amp and turned it up to the point right before we started getting feedback. Even so, the vocals were nearly impossible to hear.

Is this something that could be remedied by standing at a different distance from the mic/singing louder/turning down the other instruments' volume, or do I need some new piece of gear?