This technology wasn't designed for magicians depending on which conspiracy you subscribe to

We just borrow from alien technology like everyone else!

Please know that the larger the array the more directional the sound. Small, inexpensive units will probably not give you the results you desire as the sound has a very wide spread. Also know that you can do some serious, permanent damage to your audience's ears. I would be very careful.

Have you used large arrays? What type and was it for a show?

The smaller unit I have says keep a 6 foot direct distance, of course reflecting it adds that much more distance from ear to speaker.

These units blast high db ultrasonic sound that can not be heard but can permanently damage ears. I would personally not do that to an unconsenting person.

The larger the speaker array, the more directional, and the smaller the size of the speaker array, the less directional it is. This is fundamental physics, and cannot be bypassed, even by using phased arrays or other signal processing methods.

Commercial speaker arrays will be 12+ inches.

You can achieve the same results using a dome, probably for much less money.