I don't know if this will help...I play strings mostly, but I've found that a small sub-mixer for my own signals before they're sent to the main board or mixer gives me control over relative volumes on the fly and allows me to add additional lines in excess to what the mixer allows on its own. There's several decent small mixers which will work well, like Mackie. You can use seperate mics this way or by marking the panel with masking tape you can adjust up or down as required. Helpful? Mooh Tooh.