The Ashly XR-1001 is a Stereo 2-Way, Mono 3-Way crossover based upon a powerful state-variable filter circuit which guarantees that two adjacent frequency band outputs always remain in phase. The XR-1001 crossover offers a number of useful and unusual features, including continuous tuning, a response control, and a unique output stage which maintains low noise at any level setting. It also includes a 200:1 tuning range, output mute switch, and both TRS and XLR connectors. Like other Ashly products, your crossover features low noise and distortion, active balanced inputs, a peak level indicator, a precision regulated power supply, protection against abnormal input or output conditions, and rugged mechanical construction. Conservative design and an unusually thorough procedure for quality control have earned Ashly a reputation for dependability in the recording, sound reinforcement, and broadcast fields.Response Control; an Ashly Exclusive...This control, found adjacent to the crossover frequency control, adjusts the damping of the filter affecting the response shape of the filters at the crossover point. The dial calibrations refer to the amount of attenuation effected by the filter at the crossover frequency, i.e., a setting of 3dB means that the filter"s high-pass and low-pass outputs are each "rolled off 3dB at the crossover point". This describes Butterworth filter response, or a gentle 3dB peak at the crossover point when the two filter output signals overlap. To obtain a flat signal, or "Linkwitz-Riley" response through the crossover region, set the Response control to "6". This attenuates each output of the filter by 6dB at the crossover point (two identical signals added together yield a +6dB increase). To obtain a notch at the crossover point, turn down the response control past "6" to best suit your needs.The purpose of this control is to help offset the inaccuracies inherent in typical loudspeakers, thereby helping you to achieve a flat system response. NO