1. An active acoustic attenuation system for attenuating an input acoustic wave comprising: an output transducer introducing a canceling acoustic wave to attenuate the input acoustic wave and yield an attenuated output acoustic wave; an error transducer sensing the output acoustic wave and providing an error signal; a first adaptive filter model modeling the acoustic system and outputting a correction signal to the output transducer to introduce the canceling acoustic wave, the first adaptive filter model comprising: a first algorithm filter comprising an A filter having a filter input, a filter output, and an error input from the error transducer; a second algorithm filter comprising a B filter having a filter input from the correction signal, a filter output, and an error input from the error transducer; and a first summer having a first input from the filter output of the A filter, a second input from the filter output of the B filter, and an output outputting a first resultant sum as the correction signal; a first model copy comprising a copy of the A filter and having an input and an output; a second model copy comprising a copy of the B filter and having an input and an output; a third model copy comprising a copy of a model modeling the output transducer and the error path between the output transducer and the error transducer and having an input and a output; a second summer summing the error signal and the output of the first model copy, and supplying a second resultant sum to the filter input of the A filter and to the input of the third model copy; and a third summer summing the output of the third model copy and the output of the second model copy, and supplying a third resultant sum to the input of the first model copy and to the input of the second model copy and to the error input of the A filter for modifying the error input from the error transducer.