I think I may have put my passive monitor on the bed incorrectly. I have a wooden bunkbed that has wooden slats for support and a head board and foot board. I put the monitor on the underside of the bed on the slat closest to the headboard. The top of it is facing the floor. It is in the middle of the slat. Based on an email I got from David, it looks like it goes on top of the slat closest to the headboard on the side where a person would lay their head.
I also got a monitor for my couch but am unsure where to place it. I ripped off the dust cover one day while looking for bedbugs so I can't place it there. Where else can I put it?