Ok, I just had a bit of an "ah-ha" moment in concept.
has a good point regarding what matches the speed and pressure wave from a sub port.......a sub of course!
While we are concerned with chuffing from our ULF subs, it is the intended purpose of this project, creating air velocity, ideally moving in one direction rather than oscillating.
Could something like a set of reed valves or possibly quiet flapper valves be added to a sub enclosure to create a directional output from a port to create air waves that can be perceived by the audience? Obviously, it would have to work fairly quietly since it would be exposed to positive then negative pressures very quickly. I also imagine a stiff suspension would be needed for the sub, or perhaps something of a capacitor/diode setup so the sub isn't wrecked when moving the unloaded direction. What other challenges/concept issues are here? Not sure what kind of noises or cancellations a rig like this could introduce either.
I think something with fans will simply have too much latency and feel quite "gimickey" if reactive to program content. Those 4D theaters are programmed to have the fans spin up prior to the action on screen happening in order to compensate for the time of spinning up + time for the air to sweep across the room. A good way to get an idea of the latency is to set up an oscillating fan at the location for the output of the fan rig and let it sweep across the room and time how long it takes to feel it after the face points directly at you. Spoiler alert, not milliseconds lol. And this is with a fan that is already spun up at operating speed.
If a fan based HT air effect rig was reactive to program signal, I would prefer to have the fans at constant speed with pitch controlled blades, possibly in another room with ducting as close to the seating areas as possible to reduce latency.