My guess would be an attempt to try to cut down on high frequencies through the speakers, either noise or maybe an attempt to build a rudimentary crossover if the speakers are wired in series. Putting the two caps in series halves the capacitance, so it's effectively like putting a 75uF cap on there. But I'd be concerned about reverse biasing the caps unless there was something else connected to the side that's tied together.
No idea on the coil...