iTunes v. QuickTime

I searched for this; my apologies if it's been discussed -- just point me to where. If not....

Has anybody noticed a difference in audio quality between QuickTime and iTunes? It seems to me there's a difference and to my ear QuickTime sounds better. If true, why would that be?

I have heard people say that iTunes has an built compressor, or something to that effect, that cannot be adjusted or removed, its just part of the iTunes program, so maybe that is it?

EDIT: LATE NIGHT ..
Made no sense
Cheers

iTunes uses QuickTime for playback, so the reproduction quality is the same. However, iTunes has an equalizer and other adjustments, and QuickTime is just a straight player.

TattooedMac said:

Well Quicktime using Advanced Audio Coding (AAC) is at the core of the MPEG-4, would sound better if you have your iTunes library songs at MP3 quality.
If you made all your MP3's use the ACC codec i reckon that it would sound as good as your Quicktime experience ...

Click to expand...

That...makes...no...sense...whatsoever! My eyes cross just looking at it. MP3 and AAC are totally different formats. MP3 is part of the MPEG-2 standard, and AAC as you note is part of the MPEG-4 standard. You can't have an MP3 that uses the AAC codec.

technologist said:

iTunes uses QuickTime for playback, so the reproduction quality is the same. However, iTunes has an equalizer and other adjustments, and QuickTime is just a straight player.

Click to expand...

I'm new to iTunes and OS X .... I've been looking for an adjustable equalizer....where do I find it? I haven't found any adjustable audio qualities for either QuickTime or iTunes. Maybe that's why there's a difference on my machine.