A system comprising: an active noise controller configured to generate an anti-noise signal based on an error signal (e(n)); a loudspeaker operatively coupled to the active noise controller and configured to convert the anti-noise signal into anti-noise sound; and an acoustic error sensor operatively coupled to the active noise controller , the acoustic error sensor being configured to pick up sound and to convert the picked-up sound into the error signal (e(n)); wherein the loudspeaker comprises a front face ; the acoustic error sensor is disposed at the front face of the loudspeaker ; the active noise controller comprises at least one adaptive noise filter; the active noise controller comprises a filter controller ; the filter controller is configured to control the transfer function of the at least one adaptive noise filter based on an eigenvalue of a secondary path between the loudspeaker and the acoustic error sensor ; and the filter controller is further configured to execute an update procedure that is configured to at least one of: implement a stability condition based on the magnitude of the adaptive noise filter transfer function, the stability condition being configured to prevent the loudspeaker from overdrive; and update the transfer function of finite impulse response filters representing the at least one adaptive noise filter, the update procedure being normalized to at least one reference noise signal representative of noise from at least one noise source. an active noise controller configured to generate an anti-noise signal based on an error signal (e(n)); a loudspeaker operatively coupled to the active noise controller and configured to convert the anti-noise signal into anti-noise sound; and an acoustic error sensor operatively coupled to the active noise controller , the acoustic error sensor being configured to pick up sound and to convert the picked-up sound into the error signal (e(n)); wherein the loudspeaker comprises a front face ; the acoustic error sensor is disposed at the front face of the loudspeaker ; the active noise controller comprises at least one adaptive noise filter; the active noise controller comprises a filter controller ; the filter controller is configured to control the transfer function of the at least one adaptive noise filter based on an eigenvalue of a secondary path between the loudspeaker and the acoustic error sensor ; and the filter controller is further configured to execute an update procedure that is configured to at least one of: implement a stability condition based on the magnitude of the adaptive noise filter transfer function, the stability condition being configured to prevent the loudspeaker from overdrive; and update the transfer function of finite impulse response filters representing the at least one adaptive noise filter, the update procedure being normalized to at least one reference noise signal representative of noise from at least one noise source. implement a stability condition based on the magnitude of the adaptive noise filter transfer function, the stability condition being configured to prevent the loudspeaker from overdrive; and update the transfer function of finite impulse response filters representing the at least one adaptive noise filter, the update procedure being normalized to at least one reference noise signal representative of noise from at least one noise source. <EOS>