The Kicker KEYLOC is a 2-channel line-out converter with DSP processing that can detect, analyze, and correct the audio from your factory system, when adding aftermarket amplifiers. The KEYLOC's patent-pending KEY algorithm automatically detects and analyzes crossovers, EQ, time delay, and any all-pass filters present. It will then correct these various audio treatments, for the smoothest frequency response possible, and level-matches the left and right audio channels, giving you a clean, uncolored audio signal for your aftermarket amplifiers