EDGE is a subharmonic synth, which means that if you feed it audio the resulting output will be your audio plus extra low bass.

Unlike most bass enhancers, it doesn't just boost the bass or shape the lower frequencies. What it does is takes the input signal and creates a bass signal one (or even two) octaves lower than the original.

Because not every signal is a simple sine wave, there is input filtering which effectively gives the plugin a more simple waveform to process.