PMP4000 stereo inputs


I have a Behringer PMP4000 powered mixer which has 1-8 XLR mono mic inputs and 9/10, 11/12, 13/14 and 15/16 stereo inputs each with separate 1/4" L and R inputs. Can I use a either a 1/4" balanced or a 1/4" unbalanced jack adapters to input a microphone into the left channel of each and get the mono signal out of all speakers on the system. I would like to use 12 low impedance XLR microphones (SM57 or SM58 plus adapters) on my mixer. Am I correct in thinking it is possible?