Tamara, yes difficult to to point of impossible, but there is a difference, sound reproduction is measurable and is quantifiable, it is not a religion, nor should it be a belief, it is simply reproducing music. Get the numbers right and the result will be right, there is no voodoo involved at least in the realities of reproduction however there are many voodoos involved in the appreciation of the eventual outcome. What I am trying to say here is that many perceived 'improvements' are simply that, 'perceived' and that the 'look and feel' of an object may create a perceived improvement. This is something I have previously quoted as being 'tags' ie something that gets locked into the subconscious subliminally as being good etc. and then when seen sounds better however if not seen appears to make no difference whatever ie in a real double blind test.

John...