test 1:
your song, open it in multitrack then play it back on reaper. listen critically using speakers
then play the exported wav in vlc
switch between vlc and reaper, notice the difference
test 2:
open your exported wav into a blank project in reaper
play the exported wav in vlc
switch between vlc and reaper, notice the difference
test 3:
open any commercial release cd, export your favorite track to wav and add the wav into a blank reaper project
play wav in vlc
switch between vlc and reaper, notice the difference