To understand this story, you must first understand my setup. My bass goes directly to my head which has a patch bay for my DigiTech BP200 Multi-FX pedal. With that said, it was really late Saturday night and I wanted to play a little while without waking up my family. I tried hooking up my headphones into the headphones slot in the pedal. I dropped the headphones on the floor and I heard a "THUMP!". This was odd because the floor of my room is carpeted; thus, inhibiting loud THUMPS!. I put the headphones on my head, and I heard scratching noises. By now you must be thinking that I'm real stupid to not know that something is going on. The idea finally struck me. So I tried yelling into my headphones, my cab yelled back at me. I thought this was terribly funny and I woke up my family in my hysteria. How the headphones were amplifying my voice through the amp and stuff was beyond me. Can anyone explain how I made a PA system out of my bass rig? How do the headphones act as a microphone?