Abstract: This invention is an acoustic feedback peak elimination unit and has as its objective the elimination of unwanted acoustic resonance peaks, also called ring modes, inherent in an enclosed region where a sound amplifying system may be used. A number of separate units embodying the present invention may be used in cascade, each unit being adapted to handle a small frequency range of about an octave within the entire frequency range to be amplified, each such unit functioning at unity gain to eliminate a single feedback peak when present. In addition, the invention includes means for energizing an oscillator within its tunable frequency range so that a particular frequency may be introduced for tuning the entire sound system with desired precision.