Currently, almost all activities carried out by all parties are inseparable from the sound system. With the sound system, it is not necessary to speak loudly. There are several types of sound systems or models, ranging from the cheapest to the most expensive, with the usual quality up to good. However, there is a problem that can be obtained by a sound system that is of good quality or the usual quality, namely feedback from the speaker to the mic. Feedback will be very annoying because of the entry of sound from the speaker to the mic, which should be avoided. By using the inverse phase method and narrow bandpass filter, the simulation results can eliminate the feedback signal that is 100%. However, there are side effects on the band that occurs feedback, which is the reduction in the sound signal by the feedback power level that occurs between 30% - 100% that are in the frequency band range.