Now that I think about it, I suppose if you match the resonate frequency of the display component and its carrier it should be fairly efficient. Really cool stuff.
Other videos say that the bubble is just to protect the screen because (unsurprisingly, I would) people try to touch it - so it's not evacuated; doesn't that mean it's going to be a fairly loud 30hz speaker, effectively? (or is it just not well coupled because "speakers need to actually be designed" and it's not that bad in practice?)
