Just got Spotify Premium. Switched the music quality to extreme, and the quality isn't good?

There must be something that I have to do because the quality sounds the same, even though I switched it to extreme. I made sure that I wasn't imagining it - I played my iTunes copy and it sounded so much better.
This is the iPhone app, if that matters.
What's the solution?

Go ask Spotify.

contact-spotify-support.