I've been designated as the one to learn the ropes in Sound Reinforcement at my place of employment. So far, I've done sound for Joe Lovano, Leo Kottke and Tommy Makem, so I'm not a complete novice. I just feel that way sometimes. I'd like to appeal to the collective wisdom regarding the advisability of Mono vs. Stereo PA setup. The principal components in our system are a Mackie 1604 VLZ Pro mixer, Mackie SRM 450 powered speakers for mains and JBL Eons for monitors.