Multiresolution Coaxial Drivers Array

One approach suitable for 2D arrays is coaxial heterogeneous drivers, as depicted in Fig.9. The Kenwood KFC-1695PS, for example, provides three concentric drivers with diameters 6 1/2, 1 9/16, and 1/2 inches (75 Watts RMS). This could be packed into a rectangular panel and treated as a multiresolution Huygens Array or PBAP/VBAP system.

Figure 9: Example of a coaxial multiresolution driver geometry.

One can also imagine this type of array implemented using pipes of various diameters, with the pistons driving the larger pipes operating behind the pistons of the smaller pipes, where each piston is driven at the end of a narrow rod that passes through a small hole in the piston(s) behind.