You just raised pedantic to a whole new level. I have done fully controlled double blind testing in research lab environments, and more simplistic single blind testing too many times to count .... which is one times more blind than I expect most people commenting on this thread have ever done.
It's hard to put bias into a test process that involves nothing more than swapping cables. Great thing about that is you rarely even need to level balance, and not level balancing would increase the detection threshold not reduce it.
I am not a "casual observer".
This is wishful thinking. Remember what is being tested. What is being tested is that the person making the claim of (usually) a readily apparent audible difference is able to actually perceive in a blind situation the difference. No more. No less. Your "poisoning" actually does not fit typical psychological reactions. Normally when a persons beliefs are challenged, they will work extra hard to prove those beliefs, not fold like a wet blanket.
It's hard to put bias into a test process that involves nothing more than swapping cables. Great thing about that is you rarely even need to level balance, and not level balancing would increase the detection threshold not reduce it.
I am not a "casual observer".
For example, you’ve made it clear that you don’t think the differences between competent cables is audible. You’ve poisoned the well by conveying that to a test subject; you’ve given him a reason ("power of suggestion") to find no difference.
This is wishful thinking. Remember what is being tested. What is being tested is that the person making the claim of (usually) a readily apparent audible difference is able to actually perceive in a blind situation the difference. No more. No less. Your "poisoning" actually does not fit typical psychological reactions. Normally when a persons beliefs are challenged, they will work extra hard to prove those beliefs, not fold like a wet blanket.