Lol, I've read this forum and was expecting one of these answers Joe. I'll restate that I expected the same sound before listening and add that I prefer the Mac source at any volume to the X5 source at any volume for hires tracks.
Might get the Mrs to do some switching for me with a blind fold on. But I bet I can pick the Mac every time.
The difficulty here is deeper - and even blinded, random A/B testing is not even enough.
This is the thing that makes people cringe - our expectations shape our perception. It is not that you "imagine" something sounding better. It DOES "sound" better - TO YOU. If you believe that the $120 headphone cable made with unobtainium causes your system to sound better than the well-constructed $15 copper core cable then, for you, it actually WILL sound better. Not "you are imagining it". You expectation will change your perception in such an incredibly subtle way that you WILL ACTUALLY experience an improvement. We forget that our BRAIN is the THE most important organ involved in hearing. Not our ears - our brain.
If you are in physics, then "sound" is oscillating longitudinal air pressure. There is no brain present, and no processing. Under such conditions, everyone "hears" the same thing - and the "now" you will hear the same thing as the "future you", and also the same thing as what "past you" heard. But nothing could be farther from the truth. You and I will NEVER hear exactly what our own ears experience. That perception is filtered through layers of processing and even feedback loops (yes, your brain actually alters your ears' geometry in response to some sounds, which in turn changes how you hear those sounds, which results in changes in geometry.... you get the point).
If you even have a mild, subconscious bias (no - not even a conscious one) toward one source vs. another and you fail to do blind A/B/X testing, then your tests mean very little to nothing. The industry does not want you to believe that, but there is an enormous body of science that backs that up.
Then you get into equal loudness counters ("Fletcher-Munson Curves"), which show how our perception of volume is DIFFERENT at different frequencies, and you see why level matching is so important when testing. With source material, you have another problem with controlling variables. That great SACD you bought MIGHT sound better than its red-book counterpart because it is DSD. It might instead sound better because the mix, or the mastering on the SACD was different - with greater dynamic range. So now, to do a really good experiment, you have to control for that too.
Because here is the deal - you can be JUST as happy and have JUST as great an experience if you use rational, unbiased information to shape your expectations. Then your expectations will be more realistic - and those expectations will shape you perception - and you will have the same fantastic experiences while spending a ton less money.
That does not mean that there is no difference between products. The X5 is an excellent player. It has outstanding sound quality given reasonably high-quality source material. I have one, and bought one for a grad present for my music-major son.
