Active noise canceling is equivalent to beam shaping. It can work in headphones because you can aim the minima at the ear and the maxima away from it, but the b

Active noise canceling is equivalent to beam shaping. It can work in headphones because you can aim the minima at the ear and the maxima away from it, but the best you could achieve by adding speakers to a drone would be selecting where the energy hits. Directing everything to the upper hemisphere would be nice, but that's not how beam shaping works.