Shure DFR22 Audio Processor with Feedback Reduction - A Versatile and Powerful 2x2 Processor The DFR22 functions as an out-of-the-box 2x2 audio processor delivering superior feedback reduction combined with advanced software-configurable processing The DFR22 builds on that reputation to provide an affordable full-featured 2x2 audio processor with Shure's drag-and-drop software It's much more than feedback reduction For many jobs, it's the only audio processor you'll need Processing blocks in the DFR22 can be applied in any order, to any input or output