Active Speakers

Speakers work by modifying a magnetic coil inside a magnetic field created by a permanent magnet. The problem is that the field is only based on the incoming signal and the force on the speaker cone is limited by the power of the incoming signal. In the ideal case where the cone and coil are light weight this system works very well, but once you add mass to the system, it gets sloppy. The first part of my idea is to modify the signal to the force needed to move the speaker cone. This would require the electronics to find the rate of slope change of the incoming signal and then adjust the signal so that the required force is applied to accelerate the cone correctly. The second part of my idea is a censor feedback loop that measures the position of the cone and adjusts the correcting circuitry so the motion of the cone matches the incoming signal.

So in a worst case scenario where a square wave signal is fed into a speaker, the coil would not see a square wave, but a modified square wave punctuated by massive spikes at the changes necessary to first accelerate the cone and then decelerate the cone to follow the original square wave signal.