MXR Bass Compressor M87Bass Compressor Info: Take your favorite studio compressor to the stage with the MXR M87 Bass Compressor. A complete array of controls Attack, Release, Ratio, Input, and Output makes it easy to fine tune your sound, from subtle peak limiting to hard squashed compression effects. Its CHT Constant Headroom Technology gives you plenty of headroom and clear performance. This totally transparent compressor allows your full dynamic range to shine through