Problem with these tests is you really can't set up one that works. There are just too many emotional and physical aspects. I believe it is true that we suffer from a very short audio memory. Then there is our mood, time of day, do we like the music being used.
I also don't believe that we can do much better with measuring devices. We really don't know what all the parameters are that we need to measure. That is why JA at Stereophile is often confounded by his measurements vs what the reviewer hears. I can explain why a isolation transformer works and how it doesn't add but subtracts. I can't explain why cable makes a difference but, I know that I can hear a difference. But, I call BS on anyone that stakes the claim that it is substantial.
I also don't believe that we can do much better with measuring devices. We really don't know what all the parameters are that we need to measure. That is why JA at Stereophile is often confounded by his measurements vs what the reviewer hears. I can explain why a isolation transformer works and how it doesn't add but subtracts. I can't explain why cable makes a difference but, I know that I can hear a difference. But, I call BS on anyone that stakes the claim that it is substantial.