[codeN]

Was wondering if this is instead transformed into a wireless "near-fieldish" charging solution. Where you keep your phone on top of a speaker, then realized that the article assumed only 50% loss because of air, and in fact you can't even physically focus a 1m^2 speaker at near field.

[solistice]

That seems like an awfully Rube Goldberglike way to charge you phone though. If you're putting it on top of a speaker, why not ditch the speaker assembly and just keep the coils and there you have an inductive charging mat.