I have the EMX512 powered mixer. Right now I'm using 2 stage monitors and 2 FOH. The PA is used for vocals only right now. The manual says you can come out of the "mono out" and use an active speaker. Can you only use 1 active speaker or can you use multiples? I'm wanting to know if there is a way to run 4 stage monitors and 2 FOH with the powered mixer. If anyone is familiar with this unit any help is appreciated...thnx.