From what I understand the more I dig in and research is because its a "signature sound" thing to. For example, apple does other clarity filters and such to make it sound they way apple thinks it should sound. My assumption is they don't expect people to be using thousands of dollars in equipment to be listening to over these devices..
As stated in this thread you can bypass this by rooting the phone.. Sure its a little work now, but once done I never have to dilly dally with a computer anymore.
And yes, to answer your previous question I bought a CD with the digital download in lossless FLAK format.. using my phone I could not hear a difference from spotify 320kbs download and the FLAK.. but the CD had a night and day sound. I noticed that the sound was much better before I got to the "too loud for healthy listening" warning or whatever. So beyond this point I think the audio is compressed to sound louder without damaging equipment, not proven, just my thought on the way it sounds.
By rooting your phone and using Viper, you can get artist intended audio by bypassing the phone audio signature sound, if you will
Rooting this Galaxy is a process, lemme tell ya