[Mink]

Lately I have been listening a lot to Spotify and I must say the sound qualilty of the streaming files (320kb/ps) is mostly excellent and this brings me to this odd discovery: most of the times the music streamed by Spotify sounds superior, fuller and lusher than the same music played in iTunes or in OSX's Finder.
It doesn't make a difference if I play the uncompressed CD or AIFF file in Finder or iTunes it appears Spotify does something, maybe adds something to the streamed MP3 in order to sound rich and full, but apparantly without compromising the dynmamics of the recording.
 
This doesn't make any sense, what's happening here? Did anyone else notice this?
 
(Oh, I am listening to files on a 2007 iMac, using X-Can as DAC/headphones amp and Denon D5000 headphones)

 

[Henmyr]

It sounds to me like the volume out of spotify is greater than from my foobar ASIO or StealthAudioPlayer. That could be an explanation for the fuller sound. 
 
I measured the first guitar pluck from Mark Knopfler "Sailing to Philadelphia" with my sound level meter, and the pluck was about 2-3 dB louder from Spotify than from Foobar with asio, both on full volume. I have no idea how the rest of the frecuenzy range differs between the two.

 

[Mink]

Thanks for the reply.
The volume out in Spotify is bigger, I noticed that as well, but apart from the bigger loudness in Spotify there's an overall difference in 'presence', in Spotify the sound seems more direct, richer and somewhat softer as well, but curiously without a decrease in dynamics and soundstage.