Connecting 2 S1 Pro as monitors

Hello all. Just bought my first Bose L1 model 2 with B2 bass and T8s mixer. One question I have is what’s the best way (And best sound when playing out in bars) to hook up or connect 2 S1 Pros as monitors. I tried it last night on a practice run and the S1 pros had an almost “psychedelic” sound coming out of them which I don’t want. Shut them off and disconnected and the L1 sounded great by itself. The set up is 1 acoustic guitar, 1 mic, and 1 electric guitar. 

thank you 

Duplicate post. Please see How do I connect 2 S1 pro systems as monitors