Delay network microphones with harmonic nesting

A method for processing at least one transmitted acoustical signal that propagates through an acoustical medium, wherein one of the at least one transmitted acoustical signal is a desired transmitted acoustical signal, the method comprising:

• (a) receiving a first received signal by a first port of a first port sub-array;
• (b) receiving a second received signal by a second port of the first port sub-array, wherein the first port and the second port are spatially separated by a first horizontal distance from each other;
• (c) receiving a third received signal by a third port of a second port sub-array;
• (d) receiving a fourth received signal by a fourth port of the second port sub-array, wherein the third port and the fourth port are spatially separated by a second horizontal distance from each other;
• (e) coupling, to the first transducer, the first received signal through a first acoustical pathway and the second received signal through a second acoustical pathway;
• (f) coupling, to the second transducer, the third received signal through a third acoustical pathway and the fourth received signal through a fourth acoustical pathway;
• (g) generating, by the first transducer, a first electrical signal from the first received signal and the second received signal, wherein the first electrical signal comprises a first signal component corresponding to the desired transmitted acoustical signal over a first frequency range;
• and
• (h) generating, by the second transducer, a second electrical signal from the third received signal and the fourth received signal, wherein the second electrical signal comprises a second signal component corresponding to the desired transmitted acoustical signal over a second frequency range.

An acoustical system for processing at least one transmitted acoustical signal that propagates through an acoustical medium, wherein one of the at least one transmitted acoustical signals is a desired transmitted acoustical signal, the acoustical system comprising:

• an acoustical port array comprising a plurality of port sub-arrays, wherein the desired transmitted acoustical signal is generated by an acoustical source that is located at a horizontal angle and at a vertical angle with respect to the acoustical port array;
• a first port sub-array that is associated with the acoustical port array, the first port sub-array comprising a first port and a second port that are spatially separated by a first horizontal distance from each other and comprising a fifth port that is spatially separated from the first port by a vertical distance, the first port receiving a first received signal and the second port receiving a second received signal, wherein a first port spacing between the first and second port is approximately equal to a half wavelength that corresponds to a first upper frequency limit of the first port sub-array, the fifth port receiving a fifth received signal;
• a second port sub-array that is associated with the acoustical port array, the second port sub-array comprising a third port and a fourth port that are spatially separated by a second horizontal distance from each other and comprising a sixth port that is spatially separated from the third port by the vertical distance, the third port receiving a third received signal and the fourth port receiving a fourth received signal, wherein a second port spacing between the third and fourth port is approximately equal to a half wavelength that corresponds to a second upper frequency limit of the second port sub-array, the sixth port receiving a sixth received signal;
• a first capsule comprising a first transducer;
• a second capsule comprising a second transducer;
• a first acoustical pathway configuration comprising a first acoustical pathway that couples the first received signal to the first transducer, a second acoustical pathway that couples the second received signal to the first transducer, and a fifth acoustical pathway that couples the fifth received acoustical signal to the first transducer, wherein the first transducer generates a first electrical signal comprises a first signal component corresponding to the desired transmitted acoustical signal over a first frequency range;
• a second acoustical pathway configuration comprising a third acoustical pathway that couples the third received signal to the second transducer, a fourth acoustical pathway that couples the fourth received signal to the second transducer, and a sixth acoustical pathway that couples the sixth received acoustical signal to the second transducer, wherein the second transducer generates a second electrical signal comprises a second signal component corresponding to the desired transmitted acoustical signal over a second frequency range;
• a first bandpass filter that essentially passes electrical components over the first frequency range in order to obtain a first modified electrical signal from the first electrical signal;
• a second bandpass filter that essentially passes electrical components over the second frequency range in order to obtain a second modified electrical signal from the second electrical signal;
• an adder that combines the first modified electrical signal and the second modified electrical signal in order to provide an output signal, wherein the output signal enhances the desired transmitted acoustical signal over an output frequency range that is essentially equal to the first frequency range plus the second frequency range;
• and
• a post-processing unit that provides a desireable frequency response for at least a portion of a complete operational frequency range of the acoustical system and that reduces a first frequency component at approximately a quarter wavelength corresponding to a first upper frequency limit of the first port sub-array and a second frequency component at approximately a quarter wavelength corresponding to a second upper frequency limit of the second port sub-array.