Non linear filter with group delay at pre-response frequency for high res radio

A method for reducing the audible effect of a pre-response having energy at a pre-response frequency, the method comprising:

• introducing group delay at the pre-response frequency by filtering a digital audio signal using a digital non-minimum-phase filter having a z-transform response that includes a zero lying outside the unit circle, wherein the zero is selected to create a greater group delay at the pre-response frequency than at a frequency of 0 Hz.

A mastering processor adapted to receive a first digital audio signal and to furnish a second digital audio signal for distribution, wherein the mastering processor is configured to reduce the audible effect of a pre-response on a signal rendered from the second signal for auditioning by a listener by introducing group delay at the pre-response frequency by filtering a digital audio signal using a digital non-minimum phase filter having a z-transform response that includes a zero lying outside the unit circle whose phase response is not linearized by a zero at a reciprocal position inside the unit circle, or whose zero is selected to create a greater group delay at the pre-response frequency than at a frequency of 0 Hz.

(canceled)

(canceled)

A non-transitory computer readable medium having stored therein instructions that when executed cause a computer to perform a method for reducing the audible effect of a pre-response having energy at a pre-response frequency, comprising:

• Introducing a group delay at the pre-response frequency by filtering a digital audio signal using a digital non-minimum phase filter having a z-transform response that includes a zero lying outside the unit-circle whose phase response is not linearized by a zero at a reciprocal position inside the unit circle.