Abstract: Apparatus for eliminating feedback in stage monitors for selected musical instruments includes filter networks for attenuation of a broad frequency range including the entire range of frequencies contributing to the feedback. A combination of high order low-pass and high-pass filters is used to pass fundamental and second order components of a selected instrument, while attenuating the undesired feedback frequencies as well as extremely low range frequencies capable of damaging a speaker. A pair of passbands is provided, and a pair of frequency bands is suppressed, the two pairs providing alternate attenuation and pass-bands. Active filters having operational amplifiers and frequency selective circuits are used, along with buffering and summing circuits, to attain the desired frequency characteristic.