Earlier quoted context omitted.
Microphones have a host of issues as well. But the reason people notice the difference between cheep speakers and good ones is speakers have to deal with an instantaneous signal, if you reincode based on the characteristics of the speaker you can get a lot from even fairly cheap speakers.
How would one go about doing that?
I'm not a 100% sure, but it probably involves convolution processing, as is used in some professional speakers - particularly for room optimization[0][1].
[0] http://www.genelec.com/products/dsp-products/glm-software/ [1] http://www.youtube.com/watch?feature=player_embedded&v=k...