Preview has better sound than Itunes in OSX ??

Hello to everyone, I'm not sure if anyone noticed this, but when you're searching for some mp3s in your Mac, try to play it from preview window, and play the same song in Itunes, you will notice big difference in quality. Last time when I was importing songs into library, I have disabled loudness option, but this didn't do the trick. Does anyone know why Itunes is affecting quality of original mp3 after import. Thanks.

p.s. I'm outputting mp3 to NAD amplifier and Wharfedale Diamond speakers I can notice big difference in sound quality, if you can recommend some other player than Itunes, Songbird, or Cog , I would be grateful, because preview sounds better than all of them ????

I'd suggest checking your equalizer settings in iTunes. With it either off or set to totally flat response, there is no difference here.

The OP probably also has "SoundCheck" enabled on his iTunes, that will raise or lower volume to be in harmony with other tracks, which can also lead to a perception of lower "sound quality."

I'd assume that Preview and iTunes use the same audio engine, so it's likely that the above two answers are where to start looking. Make sure EQ is flat, and volume equalization is off, and that no other audio settings within iTunes preferences was set to on by mistake etc..

Which NAD amp are you using btw ? An integrated receiver, or separates ?

Doug

thanks for your responses, I did disable all Itunes options before import, and I'm not using equalizer (actually I got better sound with EQ on with some songs). I'm using old 3225 NAD, it's pretty good, and cheap on the internet.