> Makes me wonder if it would be possible to have a better bass response exploiting non-linear effects and doing some "magic" (that is, some heavy signal processing and feedback loop including a mic)
Non-linear effects of what? Speakers? Air? What would the microphone do? (Keep in mind that sound has to travel through air, which takes time, before it reaches the mic.)
You can already get better bass response by equalizing the signal fed to the amplifier, but the trade-off here is that it requires a bigger amplifier (and a speaker with higher Xmax).
How about using the little microphones on a Google Glass like device to provide information for negative feedback distortion cancellation? That would work better for lower frequencies. For higher frequencies, have a program adjust the audio signal in response to the user's position in the room.
See how big automotive amplifiers are for a given power. What makes home appliances big is usually a huge transformer inside (which for audio quality is good, even though switched power sources are getting better) AND the feeling that light/small is not good
A modern consumer audio system is around 80% empty space inside.
Non-linear effects of what? Speakers? Air? What would the microphone do? (Keep in mind that sound has to travel through air, which takes time, before it reaches the mic.)
You can already get better bass response by equalizing the signal fed to the amplifier, but the trade-off here is that it requires a bigger amplifier (and a speaker with higher Xmax).