The original subject of this thread concerned songs that sound fine through headphones but sound less so through some speakers. This video provides some interesting insights. One thing he explains (at 4:30) that I hadn't thought of is how with headphones your right ear hears nothing that your left ear hears and vice versa, whereas in a room with speakers both ears are hearing everything.
https://www.youtube.com/watch?v=EPJ0ebMBN50