Raindance,
I, too, believe that scientific tests should be tempered with real-world listening. That's why double-blind tests are so appropriate. They involve listening to actual music, not test tones. They involve using your ears. They involve the concept of repeatability.
If you listen to two dissimilar receivers alternately swapped into a system, and you are never aware which component is currently active, you should be able to reliably hear a difference in the sound if all receivers of similar quality don't sound the same. This is a real-world, ears-only test -- no gadgets other than an SPL meter to level match the receivers are used.
If you are not able to repeatably (beyond a certain margin of error) identify when one receiver is playing vs. the other, then that's evidence in favor of the "receivers sound the same" theory. Of course, to put more weight behind any data, you'd need many people to partake in the test.
So now all you doubters can see that, in science, you still get to use your ears. Science is just a way of doing things that tries to separate out as much bias as possible.
