the invention provides method and apparatus that utilize a plurality of port sub - arrays , in which each port sub - array comprises a plurality of acoustical ports . the ports of each port sub - array are spaced so that each port sub - array responds to acoustical signals that are generated by acoustical sources within an associated frequency range . in an embodiment of the invention , associated frequency ranges are related in a harmonic manner , in which each port sub - array corresponds to different frequency octaves . the associated frequency range is a portion of the total frequency range of an acoustical system . received acoustical signals from each of the port sub - arrays are coupled over acoustical pathways and are converted into electrical signals by capsules that may be mounted in a capsule mounting . the electrical signals may be filtered , such as to reduce spatial aliasing , and post processed to further enhance the characteristics of the signals .