In this paper, an active muffler with one control
loudspeaker inclined at 45 degree with the muffler
centerline is developed and tested. The active
muffler is attached to engine exhaust systems for
exhaust noise attenuation with a goal of attaining
broadband noise suppression. Feedback ANC with
FXLMS and Godart modified algorithms are
independently employed for controller tuning. From
experimental results it is clearly shown that although
Godart algorithm has a slightly faster transient
response than that of FXLMS for a pure tone noise
excitation, FXLMS outperforms Godart modified
algorithm in terms of noise attenuation in the overall
sense for all the noise used in the experiments.
Feedback ANC with FXLMS algorithm attained over
6 dB reductions of engine exhaust noise, whereas
feedback ANC with Godart algorithm has only 5 dB
noise attenuation. Finally, compared to results in
references [5] and [6], feedback ANC with FXLMS
has a slightly better noise attenuation performance. It
is, however, pointed out here that flow and
temperature effects are neglected in this study. These
effects will be included in the future work.