You may have already tried this, but you can get whats called Bass Shakers for your chair, and if wired properly, you will FEEL the big bump of the fireworks explosions at the end like on the actual ride. Bass shakers aren't speakers. They just shake really hard. I've seen them and almost used them in my home theater. I decided against it and bought a separate massive plate amp and mounted it in the end of my couch instead, and wired up a car audio bass bin with 2 10" liquid cooled Bazooka subs. So when the T-Rex walks past on Jurassic Park... you FEEL him walking by! They would work great for what you need.
Description says:
Connect these bass transducers like ordinary speakers to your home theater system or to a standard automotive amplifier (sold separately). When properly installed, Bass Shakers cause the area mounted upon to resonate and vibrate with the dramatic intensity of deep bass, so you'll feel a deeper connection to your favorite movie or video game. Low bass is mostly felt, rather than heard, so this resonation is perceived as clear and deep bass without the damaging effects that often accompany big sound pressure levels.
let me know if the other "idea" works out! i'm sure if you got all this stuff to come to fruition, you can add another! Great work and dedication. Your families are so lucky to have such imaginative family members!
