Originally Posted by zhenya
I'm heavily invested in the iTunes ecosystem, and I will freely admit that I actually really like using it for managing my music. Since it outputs a verified bit-perfect signal to my external DAC, I'm perfectly happy with the sound I get from it. I just want to know what the justification is for all this conversation about other programs sounding better than iTunes, since most of us here are also interested in bit-perfect. Both statements can't possibly be true.
iTunes is capable of bit-perfect playback as long as crossfade, sound check, etc., are turned off, and the volume is maxxed. But there are reasons for using a 3rd party music player with iTunes:
1. Players like BitPerfect (which I use) can bypass the Mac OS audio mixer, which means only your iTunes music is audible; no other alert sounds, beeps, pings, etc. are heard. The entire audio stream is 'hogged' by the player, and dedicated to iTunes output.
2. BitPerfect and similar players can load the upcoming audio track into RAM, and play it back from memory, rather than from a noisy hard disc. This can mean quieter, smoother playback, since the hard drive is doing less spinning and grinding.
3. Finally, with BitPerfect and other players, it is possible to have bit rates and sampling frequencies change automatically from one track to the next. In order to do this while using iTunes only, you would have to shut down iTunes, go into Audio-Midi setup, change your bit rate and sampling frequency for the track you want to play, then reopen iTunes and play the track. When you want to change back (from 24/96 to 16/44.1, for example), you'd have to do this all over again.
So, even though I don't believe these 3rd party music players actually make better sound, they are able to do things to optimize music playback, which can, in some cases, result in better audio. If you want to upsample all of your tracks to the same bit rate and sampling frequency, play your music directly from a noisy hard disk, and hear an audible alert for incoming email while listening, then iTunes on its own will work fine.
I also own Pure Music, but I wish BitPerfect had been available sooner. Both of these programs improve the sound in a small way, and equally, to my ears. BitPerfect costs $5.00, and Pure Music costs $129.00. Other players are even more expensive. For me, BitPerfect does everything a player can to optimize music playback on the Mac, is easy to set up, has no interface to clutter up iTunes, and is the cheapest, so it's the one I use.