A. Apartment living. Though I live in the ground floor I’m sure my upstairs neighbor is getting it.I suspect that killing the standing waves will also prevent them from being obvious in other's living spaces. A distributed bass array is certainly worth a try.
A standing wave is set up when the reflected wave is in phase with the incoming wave. Another way to describe this is 'superposition'. The two waves re-enforce, so you get a big wave in one area, and none in another. That big wave is far more likely to be able to move about the building.