Results for 24bit/96KHz test, vs. 16bit/44.1KHz Options

[listen]

I've been trying tigre's 24/96 test proposed in this thread, and also discussed at Afterdawn.

High definition stuff is also discussed here, here, and samples are here, but yeah, we've got a listening test thread now, so might as well use it...

My equipment is an M-Audio Revolution 7.1 feeding straight to Sennheiser HD 200 headphones. I downloaded Lovely_1.wv and used foobar2000 to do resampling, replaygaining, and ABXing. At first I was using waveOut, but then I retested them all using Kernel Streaming.

Anyway, I can ABX (with less than 1% chance of guessing):

[24/96] vs. [24/96->16/44.1->24/96] (slow resampling, dither)
[24/96] vs. [24/96->24/44.1->24/96] (slow resampling)
[24/96] vs. [24/96->16/96->24/96] (dither)

My results varied a bit, but all were significant. The first test I did, I was not expecting to hear any difference, so I was very careful, and got 12/12. Since then I've had 12/12s, 11/12s, a 10/10, and an 8/8 (got interrupted but still a valid result, and it was only a retest...)

The most consistently hearable difference for me is when I listen between 5.2 and 7.2 seconds. Some sort of drum gets hit at about 5.7s. The high definition one is somehow more convincing. Today I was thinking of the good one as a push and the bad one as a pull, but yeah that's not a very helpdul description..

I'm also hearing other differences, but it's hard to know whether I'm being tipped off by something while focussing on something else, or even what the actual difference is in objective terms.

So, what could be wrong? What else would be worth testing? I was thinking of noise shaping the output maybe...
I'm not that keen to do a huge amount of retesting with every possible combination, but if someone thinks of something important I'll be sure to check it.