Hey shadyJ,
Thanks for pointing me to the Audioholics tacticle sensations research article. While only a preliminary study with 9 people (and a couple of beers), the results are no less telling!
The size of the room will be approximately 10' x 10' x 10'. The room will be "empty". The subwoofers w/ built-in amps (and speakers) are to be built into the walls. Full-body sensations are ideal, so i might start experimenting with 100-200 Hz, per the results of the Audioholic experiment. Headphones will be worn, and the goal is for the subwoofer sound to remain nearly silent after headphones are in and on (which is why we focused on lower frequencies) while the sensations remain strong. We played with dissonance between the speakers and subwoofers, and the desired effect of a heartbeat was nearly achieved. I am nervous about pumping up the volume too loud, as I plan for most ages to be free to enter the space, from kids to older adults. Physical floor vibrations don't achieve the desired effect I am searching for.
Any advice would be immensely appreciated.
Thanks again!
Chad