Divided we stand

The task of any loudspeaker is to present a seamless field of music closely resembling the source. To do that, the full range of frequencies within the human auditory experience need to be reproduced. That's a tall order for a single moving element, yet small single drivers do it all the time, as any headphone aficionado will confirm. But, the louder the speaker must get, the more difficult the task of moving air with only one element. Of course the first speakers were "full range": one element to move the air, usually a metal diaphragm attached to a horn. Technology progressed from these glorified tin-can-and-string mechanical transducers to the electromechanical cones, coils, and magnets of today. Along the way, engineers figured out the problem with single driver speakers. They cannot move too much air without distortion. We progressed from single drivers to 2-ways, breaking the reproduction duties in half: a tweeter for the top end, a woofer for everything else. Then came 3-ways with their addition of a third driver for the midrange, and the number of drivers continued to creep upwards: super tweeters for extended high frequencies, subwoofers to capture notes so low we can only feel them. The age of the multi-driver loudspeaker was upon us. As with all things audio, we've now come full circle. One driver loudspeakers are back in vogue for small systems, claiming a level of transparency and phase accuracy that is said to be unobtainable with more drivers slicing the sound in finer increments. Tomorrow we dig a bit deeper.