We are moving our worship band from wedge monitors to headphones (Sony 7506's) and want them to be able to control their own monitor mix. I want to send 4 sub-groups to the stage that they could mix in the P4M, along with their own instrument's direct input. I know it's for PSM's, but can you plug headphones into the P4M?
You would need a multiple user headphone amp or distribution amplifier. You can not use the headphones directly with the P4M.