The volume level seems to change from song to song (and ads too)
You may notice that some music (or ads, or "sweepers") seem to be significantly louder than other recorded elements.
The problem lies in the varying levels at which CDs are mastered. Some (usually classical, jazz, and small combo vocal) are overall very quiet, to accommodate the wide dynamic range this music requires. Rock, pop, and country are usually mastered at much higher levels, apparently because mastering engineers think this makes them sound more exciting.
This will be especially apparent if you use the "mix in" function to play, for example, classical and pop music in the same stream.
Unfortunately, our sweepers and commercials are all at a standard level -- so, depending upon the type of music that surrounds them, they may sound loud, quiet, or just right.
Broadcasters (or "unicast" webcasters -- those that don't offer customization, pausing, song-skipping, etc.) are able to use technology that "normalizes" music on-the-fly, by compressing the dynamic range to make it all fit within a regulated range of volumes. While this minimizes volume swings, it reduces the dynamic range of music, an effect many people dislike.
We have been experimenting with "normalization" procedures to try to address this, reducing the volume variances yet retaining much of the dynamic range that makes music exciting. Hopefully you'll be hearing an improvement soon.