I have a friend who does PA systems for live shows, anything from a small club to an amphitheater. He was doing an outdoor show 50 miles out of town and his assistant forgot to put one of the speaker cables on the truck. He had cabling for one side of the stage but not the other. It was too late to drive back and get it, so he sent his assistant to home depot to buy a spindle of lamp cord. He ran lamp cord with duct tape over it for the full run, expecting there to be problems. When he went to do the sound check and EQ, he couldn't notice any difference at all between the two channels. The show went off perfectly.
Clearly your friend is deaf.