I found out via a press release from Meyer Sound that the Mythbusters were attacking the story of how 19Hz infrasonic sound might cause some spooky feelings for people unaware of their exposure to the sound. In 2010, in conjunction with the Gravesend Inn, I spearheaded a similar experiment, and I have an extensive writeup with videos, photos and our results starting here.
Below I have embedded Discovery's video that shows the setup of the experiment (their embedding is pretty flaky, so you can also try to view the video here). I have some further comments after the video.
The video above cuts off before they show the participants their reactions, and the results, but they did not find an effect, which is a bit of a relief for me since we didn't find anything either (our results here).
It was fascinating to watch their show though, because they did a lot of things in very similar ways to our experiment. We too had to turn our Meyer subwoofer system down because it was capable of hitting resonances in the room and making vibrations obvious to the listeners. Also, I felt similarly to Jamie in the clip above where he talks about how the 19Hz sound really makes you feel uneasy. We found that when we were meeting in the space and left the 19Hz sound on, I had to turn it off because it was pretty irritating. They discuss this further in their aftershow video here.