Adimatis,
I honestly think I tried every little thing possible since I opened the box, and I'm still experimenting. I often place harmonies off center, and I ride the volume knob constantly to give a more human feel. I blend each song on the fly to the proper level that matches my lead and I try to use the harmony in a supportive and creative way. With all that said ... I have come to the conclusion that the built in mic section on the PA900 is simply not of a high enough quality for my needs, so I was forced to augment the setup with an outboard rig.

In 45+ years of entertaining, I have never, EVER had the "perfect" setup ... there's always a compromise somewhere. At this stage in my career, portability is huge, so I have made many sacrifices to accomplish the best setup for what exists today. I just may have it now.