From the Manufacturer
The QX564i loads an ultra-efficient mid/high compression driver with a 60° (h) x 45° (v) constant directivity horn. Four Phase Aligned™ 12-in low frequency transducers arranged as vertical and horizontal pairs leverage beneficial interaction based on their spacing to extend pattern control well into the low frequency range. Because the four low frequency transducers surround the coaxial mid/high compression driver symmetrically in both the horizontal and vertical planes, response across the full frequency spectrum appears to originate from a single point in space. This basic design facilitates an idealized summation of the three frequency sections, eliminating the anomalies associated with designs that physically offset the sections. This idealized coherence applies in both the horizontal and vertical planes throughout the coverage area.