Dahlquist DQ-10, a 5-way design, became the first widely sold time-aligned loudspeaker. Each driver was mounted on its own baffle and positioned so each voice coil was aligned in the same plane, assuring the sound from each arrived at your ear at the same time. The result is an incredibly realistic sense of 3D stereo imaging. It set off a wave of various time aligned speaker designs, which many saw as a design fad, one that quickly faded. Time alignment is still controversial.