I want to clarify my opinion of blind tests as applied to audio
component comparison. They can be a useful manoeuvre on *individual,
personal* basis. Closing one's eyes helps concentration. It also
prevents sighted bias which like every other individual characteristic
affects some more some less. But closing one's eyes while listening
doesn't a "test" make. Single blind, double blind or quadruple blind
we're still individuals with different genes, abilities, experiences ,
likes and dislikes ie. hundreds of "biases". People who like chamber
music will look for and hear different kind of differences from
car-rock devotees.
When it comes to wines I'll listen to Robert Parkers of
this world sighted rather than to thousands of Gallo drinkers blind.
When it comes to violins, pianos, flutes.... take your pick and
complete the sentence. No "test". Just experience and expertise.

As for the ABX protocol with its "Listen to A, next listen
to B, next listen to X and tell if it is same as A or B" it seems to
raise insuperable problems for most people in recognising any
differences at all.
It seems that is not how people listen. That is why Sean
Olive said about his loudspeaker listening session which is AFAIK about
the only existing "scientific" DBT audio component comparison*. (I
quote from memory- not word exact. "We seldom ask for difference..We
ask for preference"). And that is why he did not use the ABX protocol.
Of course psychometricians looking for simple well defined
tasks such as human threshold in recognising, phase difference,
recognition of phase distortion etc. will do it DBT. They also have
statististically significant number of testees, rigid protocol, rigid
statistical critreria and so on. The web efforts of the ABX groupies,
Pinkerton etc are nice, amateurish reports suitable for the
free-for-all internet only-not for acceptance by an editor of a
professional journal like eg. JAES. And gossip about what "industry"
does is just gossip.
Give it up the web forum "scientists. You had plenty of years
to prove that you had a "test" that worked and you failed. In the world
of reproduction of complex musical signals there ain't no "test".There
is only individual expertise and preference.
Ludovic Mirabel