Music / sound quality much better on iphone?

So I was using a galaxy S4 for a bit, and when I got that I also got a pair of Bluetooth stereo headphones. They seemed to produce decent sound on that. After I got fed up with its size, I ditched the S4 and went back to my iPhone 5.

One thing I've noticed, is how much better the sound quality is somehow when listening to things through these headphones compared to my galaxy S4. Even though they connect via Bluetooth which is strange. I chalked it up to the EQ settings, but that is turned off. The sound just seems much richer and the bass is especially good compared to the S4. The headphones are the LG Tone+ HBS 730s I believe. Listening to them on iphone, whether it's Umano, pandora, spotify, all just seem much louder and better, the bass in particular. Is there something inherently better about iphone music?

Given its lineage stems from iPod, pretty much the Original mp3 Player, I wouldn't be surprised if they made sure that music sounds excellent, even over Bluetooth. This was a nice surprise and reaffirmed my choice to go back to iphone. I'm back for less than a week and I already forgot about the S4. It's a rare thing to be impressed / surprised by my old phone almost a year later.

Anyone else notice the sound fidelity compared to other devices? It's really quite nice.