It lets you hear more low end than your speakers can actually produce. The Harmonic Exciter, like the Bass Maximizer creates new harmonics, only in the higher registers. The result is clearer vocals, sharper percussion and more high end. It helps compensate for the loss suffered from compression schemes. The stereo section contains just one slider, which controls the stereo spread of the audio.
Higher values expand the stereo image, pushing the apparent sound source beyond the speakers.
This section has no effect on mono input signals. The loudness section brings up the level of the quieter portions of the audio to match the loudest portions. The volume section, lets you adjust the left and right output levels to compensate for the other effects. The VU meters let you monitor the levels during playback. If you overload the system, the top lights will remain on to indicate clipping of the signal.