The KEY500.1 is a smart subwoofer amplifier and audio processor in one featuring an AI-driven DSP (digital signal processing).Auto EQ Using KICKERs supplied test tones (below) the KEY automatically analyzes the audio being fed into the amplifier. Once this signal has been analyzed the amp will automatically fix peaks in the signal coming in and restore the low bass that is typically missing. In a matter of moments you get a clean even bass response from your amp!