Complex sentence: The cylindrical driver unit under the horn contained the diaphragm which was vibrated by the voice coil and sent to a flaring horn, which produced far more sound power from a given amplifier than a cone speaker.
Split into simpler sentences: The cylindrical driver unit under the horn contained the diaphragm, which the voice coil vibrated to produce sound through a flaring horn. It produced far more volume from a given amplifier than a cone speaker.