I was interested in hearing the "3D sound." The first thing I noticed was that it made the music louder. It is well-known that people generally report louder as "better." When I tried to equalize the loudness of the "with 3D" and "without 3D" sounds, I couldnt tell there was a difference, except that perhaps the high frequencies had been given a bit of a boost. It is a well-known trick of audio products claiming to process sound in special ways to just boost the treble and bass frequencies. This wasnt a scientific test, but I couldnt tell that this app was doing anything useful, but it seems that you could get whatever benefits it might have with a volume control and, more generally, an equalizer, which would probably take care of the headphone simulations, too.