The FS-4N from Nady is a feedback suppressor that offers versatile features in a slim 1RU rackmount metal chassis. It features 4 extremely narrow notch filters, each of which is independently adjustable from 60Hz to 6kHz to allow quick elimination of unwanted problem frequencies without affecting the quality of your overall sound. Controls for adjusting the notch depth on each filter let you precisely attenuate each selected frequency by up to -20dB. A push button bypass will switch all 4 of the notches in and out simultaneously for live monitoring.
The unit has standard 1/4" TRS input and output jacks for wide compatibility with a variety of systems and devices. An inline 8-band audio spectrum analyzer LED display lets you quickly identify problem frequency ranges so you can quickly react and adjust the suppressor. The unit has an internal shielded power supply with a selectable operating voltage for international use. It has a standard IEC AC socket, plus screw terminals for optional 24VDC input powering.