hifi engine

Any info on Sony APM-141ES speakers ( square drivers)

Hi, Does anyone have info on these?
I picked up a set at the thrift store for $20, they work fine, seem power hungry. Not as bright as i like in the midrange to upper midrange. low and high seem ok.
Odd looking. what is the story on them? tempted to put my old 150W yamaha on them and see how that goes.