It's a very well established condition that in order to do a valid scientific test of this sort (whether in audio or medical research or anything else) that nobody must know which is A and which is B at the time of the test, that's why it's called a double blind test.  There's more than enough literature on the subject on the web but the basic reason is that no matter how impartial the tester is they can (conciously or unconciously) influence the test results.

It doesn't make it impossible to test but it doesn't make it easy but it's the only way to do it and get valid results that no one can quibble with.

merlin, I'm not rubbishing anything - I'm just saying that there's no point doing it if it's not going to be done properly.  You can try and ridicule long established principles of experimentation all you like but it won't make a "bake-off" style blind test any more valid.

That's not really an impartial attitude to start off with is it?   That's  exactly why testing has to be double-blind so that the tester can't influence the results, whether deliberately or not.

We shouldn't be setting out to prove anything, instead we should be setting out to see if differences between cables can be reliably distinguished in DBT conditions.

Michael.